feat: add z-image support (#1020)

* add z-image support

* use flux_latent_rgb_proj for z-image

* fix qwen3 rope type

* add support for qwen3 4b gguf

* add support for diffusers format lora

* fix nan issue that occurs when using CUDA with k-quants weights

* add z-image docs

README.md

@@ -45,6 +45,7 @@ API and command-line option may change frequently.***
     - [Chroma](./docs/chroma.md)
     - [Chroma1-Radiance](./docs/chroma_radiance.md)
     - [Qwen Image](./docs/qwen_image.md)
+    - [Z-Image](./docs/z_image.md)
   - Image Edit Models
     - [FLUX.1-Kontext-dev](./docs/kontext.md)
     - [Qwen Image Edit/Qwen Image Edit 2509](./docs/qwen_image_edit.md)
@@ -129,6 +130,7 @@ If you want to improve performance or reduce VRAM/RAM usage, please refer to [pe
 - [🔥Qwen Image](./docs/qwen_image.md)
 - [🔥Qwen Image Edit/Qwen Image Edit 2509](./docs/qwen_image_edit.md)
 - [🔥Wan2.1/Wan2.2](./docs/wan.md)
+- [🔥Z-Image](./docs/z_image.md)
 - [LoRA](./docs/lora.md)
 - [LCM/LCM-LoRA](./docs/lcm.md)
 - [Using PhotoMaker to personalize image generation](./docs/photo_maker.md)

conditioner.hpp

@@ -1638,6 +1638,8 @@ struct LLMEmbedder : public Conditioner {
         LLM::LLMArch arch = LLM::LLMArch::QWEN2_5_VL;
         if (sd_version_is_flux2(version)) {
             arch = LLM::LLMArch::MISTRAL_SMALL_3_2;
+        } else if (sd_version_is_z_image(version)) {
+            arch = LLM::LLMArch::QWEN3;
         }
         if (arch == LLM::LLMArch::MISTRAL_SMALL_3_2) {
             tokenizer = std::make_shared<LLM::MistralTokenizer>();
@@ -1785,9 +1787,31 @@ struct LLMEmbedder : public Conditioner {
             prompt = "<|im_start|>system\nDescribe the key features of the input image (color, shape, size, texture, objects, background), then explain how the user's text instruction should alter or modify the image. Generate a new image that meets the user's requirements while maintaining consistency with the original input where appropriate.<|im_end|>\n<|im_start|>user\n";
             prompt += img_prompt;
 
-            prompt_attn_range.first = prompt.size();
+            prompt_attn_range.first = static_cast<int>(prompt.size());
             prompt += conditioner_params.text;
-            prompt_attn_range.second = prompt.size();
+            prompt_attn_range.second = static_cast<int>(prompt.size());
+
+            prompt += "<|im_end|>\n<|im_start|>assistant\n";
+        } else if (sd_version_is_flux2(version)) {
+            prompt_template_encode_start_idx = 0;
+            out_layers                       = {10, 20, 30};
+
+            prompt = "[SYSTEM_PROMPT]You are an AI that reasons about image descriptions. You give structured responses focusing on object relationships, object\nattribution and actions without speculation.[/SYSTEM_PROMPT][INST]";
+
+            prompt_attn_range.first = static_cast<int>(prompt.size());
+            prompt += conditioner_params.text;
+            prompt_attn_range.second = static_cast<int>(prompt.size());
+
+            prompt += "[/INST]";
+        } else if (sd_version_is_z_image(version)) {
+            prompt_template_encode_start_idx = 0;
+            out_layers                       = {35};  // -2
+
+            prompt = "<|im_start|>user\n";
+
+            prompt_attn_range.first = static_cast<int>(prompt.size());
+            prompt += conditioner_params.text;
+            prompt_attn_range.second = static_cast<int>(prompt.size());
 
             prompt += "<|im_end|>\n<|im_start|>assistant\n";
         } else if (sd_version_is_flux2(version)) {
@@ -1806,9 +1830,9 @@ struct LLMEmbedder : public Conditioner {
 
             prompt = "<|im_start|>system\nDescribe the image by detailing the color, shape, size, texture, quantity, text, spatial relationships of the objects and background:<|im_end|>\n<|im_start|>user\n";
 
-            prompt_attn_range.first = prompt.size();
+            prompt_attn_range.first = static_cast<int>(prompt.size());
             prompt += conditioner_params.text;
-            prompt_attn_range.second = prompt.size();
+            prompt_attn_range.second = static_cast<int>(prompt.size());
 
             prompt += "<|im_end|>\n<|im_start|>assistant\n";
         }

diffusion_model.hpp

@@ -6,6 +6,7 @@
 #include "qwen_image.hpp"
 #include "unet.hpp"
 #include "wan.hpp"
+#include "z_image.hpp"
 
 struct DiffusionParams {
     struct ggml_tensor* x                     = nullptr;
@@ -357,4 +358,67 @@ struct QwenImageModel : public DiffusionModel {
     }
 };
 
+struct ZImageModel : public DiffusionModel {
+    std::string prefix;
+    ZImage::ZImageRunner z_image;
+
+    ZImageModel(ggml_backend_t backend,
+                bool offload_params_to_cpu,
+                const String2TensorStorage& tensor_storage_map = {},
+                const std::string prefix                       = "model.diffusion_model",
+                SDVersion version                              = VERSION_Z_IMAGE)
+        : prefix(prefix), z_image(backend, offload_params_to_cpu, tensor_storage_map, prefix, version) {
+    }
+
+    std::string get_desc() override {
+        return z_image.get_desc();
+    }
+
+    void alloc_params_buffer() override {
+        z_image.alloc_params_buffer();
+    }
+
+    void free_params_buffer() override {
+        z_image.free_params_buffer();
+    }
+
+    void free_compute_buffer() override {
+        z_image.free_compute_buffer();
+    }
+
+    void get_param_tensors(std::map<std::string, struct ggml_tensor*>& tensors) override {
+        z_image.get_param_tensors(tensors, prefix);
+    }
+
+    size_t get_params_buffer_size() override {
+        return z_image.get_params_buffer_size();
+    }
+
+    void set_weight_adapter(const std::shared_ptr<WeightAdapter>& adapter) override {
+        z_image.set_weight_adapter(adapter);
+    }
+
+    int64_t get_adm_in_channels() override {
+        return 768;
+    }
+
+    void set_flash_attn_enabled(bool enabled) {
+        z_image.set_flash_attention_enabled(enabled);
+    }
+
+    void compute(int n_threads,
+                 DiffusionParams diffusion_params,
+                 struct ggml_tensor** output     = nullptr,
+                 struct ggml_context* output_ctx = nullptr) override {
+        return z_image.compute(n_threads,
+                               diffusion_params.x,
+                               diffusion_params.timesteps,
+                               diffusion_params.context,
+                               diffusion_params.ref_latents,
+                               true,  // increase_ref_index
+                               output,
+                               output_ctx);
+    }
+};
+
 #endif

docs/z_image.md

@@ -0,0 +1,28 @@
+# How to Use
+
+You can run Z-Image with stable-diffusion.cpp on GPUs with 4GB of VRAM — or even less.
+
+## Download weights
+
+- Download Z-Image-Turbo
+    - safetensors: https://huggingface.co/Comfy-Org/z_image_turbo/tree/main/split_files/diffusion_models
+    - gguf: https://huggingface.co/leejet/Z-Image-Turbo-GGUF/tree/main
+- Download vae
+    - safetensors: https://huggingface.co/black-forest-labs/FLUX.1-schnell/tree/main
+- Download Qwen3 4b
+    - safetensors: https://huggingface.co/Comfy-Org/z_image_turbo/tree/main/split_files/text_encoders
+    - gguf: https://huggingface.co/unsloth/Qwen3-4B-Instruct-2507-GGUF/tree/main
+
+## Examples
+
+```
+.\bin\Release\sd.exe --diffusion-model  z_image_turbo-Q3_K.gguf --vae ..\..\ComfyUI\models\vae\ae.sft  --llm ..\..\ComfyUI\models\text_encoders\Qwen3-4B-Instruct-2507-Q4_K_M.gguf -p "A cinematic, melancholic photograph of a solitary hooded figure walking through a sprawling, rain-slicked metropolis at night. The city lights are a chaotic blur of neon orange and cool blue, reflecting on the wet asphalt. The scene evokes a sense of being a single component in a vast machine. Superimposed over the image in a sleek, modern, slightly glitched font is the philosophical quote: 'THE CITY IS A CIRCUIT BOARD, AND I AM A BROKEN TRANSISTOR.' -- moody, atmospheric, profound, dark academic" --cfg-scale 1.0 -v --offload-to-cpu --diffusion-fa -H 1024 -W 512
+```
+
+<img width="256" alt="z-image example" src="../assets/z_image/q3_K.png" />
+
+## Comparison of Different Quantization Types
+
+| bf16 | q8_0 | q6_K | q5_0 | q4_K | q4_0 | q3_K | q2_K|
+|---|---|---|---|---|---|---|---|
+| <img width="256" alt="bf16" src="../assets/z_image/bf16.png" /> | <img width="256" alt="q8_0" src="../assets/z_image/q8_0.png" /> | <img width="256" alt="q6_K" src="../assets/z_image/q6_K.png" /> | <img width="256" alt="q5_0" src="../assets/z_image/q5_0.png" />  | <img width="256" alt="q4_K" src="../assets/z_image/q4_K.png" /> | <img width="256" alt="q4_0" src="../assets/z_image/q4_0.png" /> | <img width="256" alt="q3_K" src="../assets/z_image/q3_K.png" /> | <img width="256" alt="q2_K" src="../assets/z_image/q2_K.png" /> |

llm.hpp

@@ -1,5 +1,5 @@
-#ifndef __QWENVL_HPP__
+#ifndef __LLM_HPP__
-#define __QWENVL_HPP__
+#define __LLM_HPP__
 
 #include <algorithm>
 #include <fstream>
@@ -256,7 +256,7 @@ namespace LLM {
                 ss << "\"" << token << "\", ";
             }
             ss << "]";
-            // LOG_DEBUG("split prompt \"%s\" to tokens %s", original_text.c_str(), ss.str().c_str());
+            LOG_DEBUG("split prompt \"%s\" to tokens %s", original_text.c_str(), ss.str().c_str());
             // printf("split prompt \"%s\" to tokens %s \n", original_text.c_str(), ss.str().c_str());
             return bpe_tokens;
         }
@@ -469,12 +469,14 @@ namespace LLM {
 
     enum class LLMArch {
         QWEN2_5_VL,
+        QWEN3,
         MISTRAL_SMALL_3_2,
         ARCH_COUNT,
     };
 
     static const char* llm_arch_to_str[] = {
         "qwen2.5vl",
+        "qwen3",
         "mistral_small3.2",
     };
 
@@ -501,6 +503,7 @@ namespace LLM {
         int64_t num_kv_heads      = 4;
         int64_t head_dim          = 128;
         bool qkv_bias             = true;
+        bool qk_norm              = false;
         int64_t vocab_size        = 152064;
         float rms_norm_eps        = 1e-06f;
         LLMVisionParams vision;
@@ -813,14 +816,19 @@ namespace LLM {
         int64_t head_dim;
         int64_t num_heads;
         int64_t num_kv_heads;
+        bool qk_norm;
 
     public:
         Attention(const LLMParams& params)
-            : num_heads(params.num_heads), num_kv_heads(params.num_kv_heads), head_dim(params.head_dim), arch(params.arch) {
+            : arch(params.arch), num_heads(params.num_heads), num_kv_heads(params.num_kv_heads), head_dim(params.head_dim), qk_norm(params.qk_norm) {
             blocks["q_proj"] = std::make_shared<Linear>(params.hidden_size, num_heads * head_dim, params.qkv_bias);
             blocks["k_proj"] = std::make_shared<Linear>(params.hidden_size, num_kv_heads * head_dim, params.qkv_bias);
             blocks["v_proj"] = std::make_shared<Linear>(params.hidden_size, num_kv_heads * head_dim, params.qkv_bias);
             blocks["o_proj"] = std::make_shared<Linear>(num_heads * head_dim, params.hidden_size, false);
+            if (params.qk_norm) {
+                blocks["q_norm"] = std::make_shared<RMSNorm>(head_dim, params.rms_norm_eps);
+                blocks["k_norm"] = std::make_shared<RMSNorm>(head_dim, params.rms_norm_eps);
+            }
         }
 
         struct ggml_tensor* forward(GGMLRunnerContext* ctx,
@@ -842,9 +850,20 @@ namespace LLM {
             k = ggml_reshape_4d(ctx->ggml_ctx, k, head_dim, num_kv_heads, n_token, N);  // [N, n_token, num_kv_heads, head_dim]
             v = ggml_reshape_4d(ctx->ggml_ctx, v, head_dim, num_kv_heads, n_token, N);  // [N, n_token, num_kv_heads, head_dim]
 
+            if (qk_norm) {
+                auto q_norm = std::dynamic_pointer_cast<RMSNorm>(blocks["q_norm"]);
+                auto k_norm = std::dynamic_pointer_cast<RMSNorm>(blocks["k_norm"]);
+
+                q = q_norm->forward(ctx, q);
+                k = k_norm->forward(ctx, k);
+            }
+
             if (arch == LLMArch::MISTRAL_SMALL_3_2) {
                 q = ggml_rope_ext(ctx->ggml_ctx, q, input_pos, nullptr, 128, GGML_ROPE_TYPE_NORMAL, 131072, 1000000000.f, 1.f, 0.f, 1.f, 32.f, 1.f);
                 k = ggml_rope_ext(ctx->ggml_ctx, k, input_pos, nullptr, 128, GGML_ROPE_TYPE_NORMAL, 131072, 1000000000.f, 1.f, 0.f, 1.f, 32.f, 1.f);
+            } else if (arch == LLMArch::QWEN3) {
+                q = ggml_rope_ext(ctx->ggml_ctx, q, input_pos, nullptr, 128, GGML_ROPE_TYPE_NEOX, 151936, 1000000.f, 1.f, 0.f, 1.f, 32.f, 1.f);
+                k = ggml_rope_ext(ctx->ggml_ctx, k, input_pos, nullptr, 128, GGML_ROPE_TYPE_NEOX, 151936, 1000000.f, 1.f, 0.f, 1.f, 32.f, 1.f);
             } else {
                 int sections[4] = {16, 24, 24, 0};
                 q               = ggml_rope_multi(ctx->ggml_ctx, q, input_pos, nullptr, head_dim, sections, GGML_ROPE_TYPE_MROPE, 128000, 1000000.f, 1.f, 0.f, 1.f, 32.f, 1.f);
@@ -1063,6 +1082,17 @@ namespace LLM {
                 params.qkv_bias          = false;
                 params.vocab_size        = 131072;
                 params.rms_norm_eps      = 1e-5f;
+            } else if (arch == LLMArch::QWEN3) {
+                params.num_layers        = 36;
+                params.hidden_size       = 2560;
+                params.intermediate_size = 9728;
+                params.head_dim          = 128;
+                params.num_heads         = 32;
+                params.num_kv_heads      = 8;
+                params.qkv_bias          = false;
+                params.qk_norm           = true;
+                params.vocab_size        = 151936;
+                params.rms_norm_eps      = 1e-6f;
             }
             bool have_vision_weight = false;
             bool llama_cpp_style    = false;
@@ -1132,7 +1162,7 @@ namespace LLM {
             }
 
             int64_t n_tokens = input_ids->ne[0];
-            if (params.arch == LLMArch::MISTRAL_SMALL_3_2) {
+            if (params.arch == LLMArch::MISTRAL_SMALL_3_2 || params.arch == LLMArch::QWEN3) {
                 input_pos_vec.resize(n_tokens);
                 for (int i = 0; i < n_tokens; ++i) {
                     input_pos_vec[i] = i;
@@ -1420,7 +1450,8 @@ namespace LLM {
 
             struct ggml_context* work_ctx = ggml_init(params);
             GGML_ASSERT(work_ctx != nullptr);
-            bool test_mistral          = true;
+            bool test_mistral          = false;
+            bool test_qwen3            = true;
             bool test_vit              = false;
             bool test_decoder_with_vit = false;
 
@@ -1455,9 +1486,9 @@ namespace LLM {
                 std::pair<int, int> prompt_attn_range;
                 std::string text = "<|im_start|>system\nDescribe the key features of the input image (color, shape, size, texture, objects, background), then explain how the user's text instruction should alter or modify the image. Generate a new image that meets the user's requirements while maintaining consistency with the original input where appropriate.<|im_end|>\n<|im_start|>user\n";
                 text += img_prompt;
-                prompt_attn_range.first = text.size();
+                prompt_attn_range.first = static_cast<int>(text.size());
                 text += "change 'flux.cpp' to 'edit.cpp'";
-                prompt_attn_range.second = text.size();
+                prompt_attn_range.second = static_cast<int>(text.size());
                 text += "<|im_end|>\n<|im_start|>assistant\n";
 
                 auto tokens_and_weights     = tokenize(text, prompt_attn_range, 0, false);
@@ -1496,9 +1527,9 @@ namespace LLM {
             } else if (test_mistral) {
                 std::pair<int, int> prompt_attn_range;
                 std::string text        = "[SYSTEM_PROMPT]You are an AI that reasons about image descriptions. You give structured responses focusing on object relationships, object\nattribution and actions without speculation.[/SYSTEM_PROMPT][INST]";
-                prompt_attn_range.first = text.size();
+                prompt_attn_range.first = static_cast<int>(text.size());
                 text += "a lovely cat";
-                prompt_attn_range.second = text.size();
+                prompt_attn_range.second = static_cast<int>(text.size());
                 text += "[/INST]";
                 auto tokens_and_weights     = tokenize(text, prompt_attn_range, 0, false);
                 std::vector<int>& tokens    = std::get<0>(tokens_and_weights);
@@ -1514,14 +1545,37 @@ namespace LLM {
                 model.compute(8, input_ids, {}, {10, 20, 30}, &out, work_ctx);
                 int t1 = ggml_time_ms();
 
+                print_ggml_tensor(out);
+                LOG_DEBUG("llm test done in %dms", t1 - t0);
+            } else if (test_qwen3) {
+                std::pair<int, int> prompt_attn_range;
+                std::string text        = "<|im_start|>user\n";
+                prompt_attn_range.first = static_cast<int>(text.size());
+                text += "a lovely cat";
+                prompt_attn_range.second = static_cast<int>(text.size());
+                text += "<|im_end|>\n<|im_start|>assistant\n";
+                auto tokens_and_weights     = tokenize(text, prompt_attn_range, 0, false);
+                std::vector<int>& tokens    = std::get<0>(tokens_and_weights);
+                std::vector<float>& weights = std::get<1>(tokens_and_weights);
+                for (auto token : tokens) {
+                    printf("%d ", token);
+                }
+                printf("\n");
+                auto input_ids          = vector_to_ggml_tensor_i32(work_ctx, tokens);
+                struct ggml_tensor* out = nullptr;
+
+                int t0 = ggml_time_ms();
+                model.compute(8, input_ids, {}, {35}, &out, work_ctx);
+                int t1 = ggml_time_ms();
+
                 print_ggml_tensor(out);
                 LOG_DEBUG("llm test done in %dms", t1 - t0);
             } else {
                 std::pair<int, int> prompt_attn_range;
                 std::string text        = "<|im_start|>system\nDescribe the image by detailing the color, shape, size, texture, quantity, text, spatial relationships of the objects and background:<|im_end|>\n<|im_start|>user\n";
-                prompt_attn_range.first = text.size();
+                prompt_attn_range.first = static_cast<int>(text.size());
                 text += "a lovely cat";
-                prompt_attn_range.second = text.size();
+                prompt_attn_range.second = static_cast<int>(text.size());
                 text += "<|im_end|>\n<|im_start|>assistant\n";
                 auto tokens_and_weights     = tokenize(text, prompt_attn_range, 0, false);
                 std::vector<int>& tokens    = std::get<0>(tokens_and_weights);
@@ -1563,7 +1617,7 @@ namespace LLM {
                 }
             }
 
-            LLMArch arch = LLMArch::MISTRAL_SMALL_3_2;
+            LLMArch arch = LLMArch::QWEN3;
 
             std::shared_ptr<LLMEmbedder> llm = std::make_shared<LLMEmbedder>(arch,
                                                                              backend,
@@ -1587,6 +1641,6 @@ namespace LLM {
             llm->test();
         }
     };
-};  // Qwen
+};  // LLM
 
-#endif  // __QWENVL_HPP__
+#endif  // __LLM_HPP__

mmdit.hpp

@@ -101,10 +101,14 @@ protected:
 
 public:
     TimestepEmbedder(int64_t hidden_size,
-                     int64_t frequency_embedding_size = 256)
+                     int64_t frequency_embedding_size = 256,
+                     int64_t out_channels             = 0)
         : frequency_embedding_size(frequency_embedding_size) {
+        if (out_channels <= 0) {
+            out_channels = hidden_size;
+        }
         blocks["mlp.0"] = std::shared_ptr<GGMLBlock>(new Linear(frequency_embedding_size, hidden_size, true, true));
-        blocks["mlp.2"] = std::shared_ptr<GGMLBlock>(new Linear(hidden_size, hidden_size, true, true));
+        blocks["mlp.2"] = std::shared_ptr<GGMLBlock>(new Linear(hidden_size, out_channels, true, true));
     }
 
     struct ggml_tensor* forward(GGMLRunnerContext* ctx, struct ggml_tensor* t) {

model.cpp

@@ -1067,6 +1067,9 @@ SDVersion ModelLoader::get_sd_version() {
             if (tensor_storage.name.find("model.diffusion_model.double_stream_modulation_img.lin.weight") != std::string::npos) {
                 return VERSION_FLUX2;
             }
+            if (tensor_storage.name.find("model.diffusion_model.cap_embedder.0.weight") != std::string::npos) {
+                return VERSION_Z_IMAGE;
+            }
             if (tensor_storage.name.find("model.diffusion_model.blocks.0.cross_attn.norm_k.weight") != std::string::npos) {
                 is_wan = true;
             }

model.h

@@ -44,6 +44,7 @@ enum SDVersion {
     VERSION_WAN2_2_TI2V,
     VERSION_QWEN_IMAGE,
     VERSION_FLUX2,
+    VERSION_Z_IMAGE,
     VERSION_COUNT,
 };
 
@@ -116,6 +117,13 @@ static inline bool sd_version_is_qwen_image(SDVersion version) {
     return false;
 }
 
+static inline bool sd_version_is_z_image(SDVersion version) {
+    if (version == VERSION_Z_IMAGE) {
+        return true;
+    }
+    return false;
+}
+
 static inline bool sd_version_is_inpaint(SDVersion version) {
     if (version == VERSION_SD1_INPAINT ||
         version == VERSION_SD2_INPAINT ||
@@ -132,7 +140,8 @@ static inline bool sd_version_is_dit(SDVersion version) {
         sd_version_is_flux2(version) ||
         sd_version_is_sd3(version) ||
         sd_version_is_wan(version) ||
-        sd_version_is_qwen_image(version)) {
+        sd_version_is_qwen_image(version) ||
+        sd_version_is_z_image(version)) {
         return true;
     }
     return false;

name_conversion.cpp

@@ -133,6 +133,8 @@ std::string convert_cond_stage_model_name(std::string name, std::string prefix)
         {"attn_q.", "self_attn.q_proj."},
         {"attn_k.", "self_attn.k_proj."},
         {"attn_v.", "self_attn.v_proj."},
+        {"attn_q_norm.", "self_attn.q_norm."},
+        {"attn_k_norm.", "self_attn.k_norm."},
         {"attn_output.", "self_attn.o_proj."},
         {"attn_norm.", "input_layernorm."},
         {"ffn_down.", "mlp.down_proj."},
@@ -613,6 +615,44 @@ std::string convert_diffusers_dit_to_original_flux(std::string name) {
     return name;
 }
 
+std::string convert_diffusers_dit_to_original_lumina2(std::string name) {
+    int num_layers         = 30;
+    int num_refiner_layers = 2;
+    static std::unordered_map<std::string, std::string> z_image_name_map;
+
+    if (z_image_name_map.empty()) {
+        z_image_name_map["all_x_embedder.2-1."]  = "x_embedder.";
+        z_image_name_map["all_final_layer.2-1."] = "final_layer.";
+
+        // --- transformer blocks ---
+        auto add_attention_map = [&](const std::string& prefix, int num) {
+            for (int i = 0; i < num; ++i) {
+                std::string block_prefix = prefix + std::to_string(i) + ".";
+                std::string dst_prefix   = prefix + std::to_string(i) + ".";
+
+                z_image_name_map[block_prefix + "attention.norm_q."]   = dst_prefix + "attention.q_norm.";
+                z_image_name_map[block_prefix + "attention.norm_k."]   = dst_prefix + "attention.k_norm.";
+                z_image_name_map[block_prefix + "attention.to_out.0."] = dst_prefix + "attention.out.";
+
+                z_image_name_map[block_prefix + "attention.to_q.weight"] = dst_prefix + "attention.qkv.weight";
+                z_image_name_map[block_prefix + "attention.to_q.bias"]   = dst_prefix + "attention.qkv.bias";
+                z_image_name_map[block_prefix + "attention.to_k.weight"] = dst_prefix + "attention.qkv.weight.1";
+                z_image_name_map[block_prefix + "attention.to_k.bias"]   = dst_prefix + "attention.qkv.bias.1";
+                z_image_name_map[block_prefix + "attention.to_v.weight"] = dst_prefix + "attention.qkv.weight.2";
+                z_image_name_map[block_prefix + "attention.to_v.bias"]   = dst_prefix + "attention.qkv.bias.2";
+            }
+        };
+
+        add_attention_map("noise_refiner.", num_refiner_layers);
+        add_attention_map("context_refiner.", num_refiner_layers);
+        add_attention_map("layers.", num_layers);
+    }
+
+    replace_with_prefix_map(name, z_image_name_map);
+
+    return name;
+}
+
 std::string convert_diffusion_model_name(std::string name, std::string prefix, SDVersion version) {
     if (sd_version_is_sd1(version) || sd_version_is_sd2(version)) {
         name = convert_diffusers_unet_to_original_sd1(name);
@@ -622,6 +662,8 @@ std::string convert_diffusion_model_name(std::string name, std::string prefix, S
         name = convert_diffusers_dit_to_original_sd3(name);
     } else if (sd_version_is_flux(version) || sd_version_is_flux2(version)) {
         name = convert_diffusers_dit_to_original_flux(name);
+    } else if (sd_version_is_z_image(version)) {
+        name = convert_diffusers_dit_to_original_lumina2(name);
     }
     return name;
 }

rope.hpp

@@ -379,6 +379,55 @@ namespace Rope {
         return embed_nd(ids, 1, theta, axes_dim);
     }
 
+    __STATIC_INLINE__ int bound_mod(int a, int m) {
+        return (m - (a % m)) % m;
+    }
+
+    __STATIC_INLINE__ std::vector<std::vector<float>> gen_z_image_ids(int h,
+                                                                      int w,
+                                                                      int patch_size,
+                                                                      int bs,
+                                                                      int context_len,
+                                                                      int seq_multi_of,
+                                                                      const std::vector<ggml_tensor*>& ref_latents,
+                                                                      bool increase_ref_index) {
+        int padded_context_len = context_len + bound_mod(context_len, seq_multi_of);
+        auto txt_ids           = std::vector<std::vector<float>>(bs * padded_context_len, std::vector<float>(3, 0.0f));
+        for (int i = 0; i < bs * padded_context_len; i++) {
+            txt_ids[i][0] = (i % padded_context_len) + 1.f;
+        }
+
+        int axes_dim_num = 3;
+        int index        = padded_context_len + 1;
+        auto img_ids     = gen_flux_img_ids(h, w, patch_size, bs, axes_dim_num, index);
+
+        int img_pad_len = bound_mod(static_cast<int>(img_ids.size() / bs), seq_multi_of);
+        if (img_pad_len > 0) {
+            std::vector<std::vector<float>> img_pad_ids(bs * img_pad_len, std::vector<float>(3, 0.f));
+            img_ids = concat_ids(img_ids, img_pad_ids, bs);
+        }
+
+        auto ids = concat_ids(txt_ids, img_ids, bs);
+
+        // ignore ref_latents for now
+        return ids;
+    }
+
+    // Generate z_image positional embeddings
+    __STATIC_INLINE__ std::vector<float> gen_z_image_pe(int h,
+                                                        int w,
+                                                        int patch_size,
+                                                        int bs,
+                                                        int context_len,
+                                                        int seq_multi_of,
+                                                        const std::vector<ggml_tensor*>& ref_latents,
+                                                        bool increase_ref_index,
+                                                        int theta,
+                                                        const std::vector<int>& axes_dim) {
+        std::vector<std::vector<float>> ids = gen_z_image_ids(h, w, patch_size, bs, context_len, seq_multi_of, ref_latents, increase_ref_index);
+        return embed_nd(ids, bs, theta, axes_dim);
+    }
+
     __STATIC_INLINE__ struct ggml_tensor* apply_rope(struct ggml_context* ctx,
                                                      struct ggml_tensor* x,
                                                      struct ggml_tensor* pe,

stable-diffusion.cpp

@@ -45,6 +45,7 @@ const char* model_version_to_str[] = {
     "Wan 2.2 TI2V",
     "Qwen Image",
     "Flux.2",
+    "Z-Image",
 };
 
 const char* sampling_methods_str[] = {
@@ -377,7 +378,7 @@ public:
         } else if (sd_version_is_sd3(version)) {
             scale_factor = 1.5305f;
             shift_factor = 0.0609f;
-        } else if (sd_version_is_flux(version)) {
+        } else if (sd_version_is_flux(version) || sd_version_is_z_image(version)) {
             scale_factor = 0.3611f;
             shift_factor = 0.1159f;
         } else if (sd_version_is_wan(version) ||
@@ -495,6 +496,16 @@ public:
                                                                    tensor_storage_map,
                                                                    "model.diffusion_model",
                                                                    version);
+            } else if (sd_version_is_z_image(version)) {
+                cond_stage_model = std::make_shared<LLMEmbedder>(clip_backend,
+                                                                 offload_params_to_cpu,
+                                                                 tensor_storage_map,
+                                                                 version);
+                diffusion_model  = std::make_shared<ZImageModel>(backend,
+                                                                offload_params_to_cpu,
+                                                                tensor_storage_map,
+                                                                "model.diffusion_model",
+                                                                version);
             } else {  // SD1.x SD2.x SDXL
                 if (strstr(SAFE_STR(sd_ctx_params->photo_maker_path), "v2")) {
                     cond_stage_model = std::make_shared<FrozenCLIPEmbedderWithCustomWords>(clip_backend,
@@ -868,6 +879,13 @@ public:
                     shift = 3.0;
                 }
                 denoiser = std::make_shared<DiscreteFlowDenoiser>(shift);
+            } else if (sd_version_is_z_image(version)) {
+                LOG_INFO("running in FLOW mode");
+                float shift = sd_ctx_params->flow_shift;
+                if (shift == INFINITY) {
+                    shift = 3.0f;
+                }
+                denoiser = std::make_shared<DiscreteFlowDenoiser>(shift);
             } else if (is_using_v_parameterization) {
                 LOG_INFO("running in v-prediction mode");
                 denoiser = std::make_shared<CompVisVDenoiser>();
@@ -1337,7 +1355,7 @@ public:
                 if (sd_version_is_sd3(version)) {
                     latent_rgb_proj = sd3_latent_rgb_proj;
                     latent_rgb_bias = sd3_latent_rgb_bias;
-                } else if (sd_version_is_flux(version)) {
+                } else if (sd_version_is_flux(version) || sd_version_is_z_image(version)) {
                     latent_rgb_proj = flux_latent_rgb_proj;
                     latent_rgb_bias = flux_latent_rgb_bias;
                 } else if (sd_version_is_wan(version) || sd_version_is_qwen_image(version)) {
@@ -1638,6 +1656,8 @@ public:
                 shifted_t             = std::max((int64_t)0, std::min((int64_t)(TIMESTEPS - 1), shifted_t));
                 LOG_DEBUG("shifting timestep from %.2f to %" PRId64 " (sigma: %.4f)", t, shifted_t, sigma);
                 timesteps_vec.assign(1, (float)shifted_t);
+            } else if (sd_version_is_z_image(version)) {
+                timesteps_vec.assign(1, 1000.f - t);
             } else {
                 timesteps_vec.assign(1, t);
             }

z_image.hpp

@@ -0,0 +1,670 @@
+#ifndef __Z_IMAGE_HPP__
+#define __Z_IMAGE_HPP__
+
+#include <algorithm>
+
+#include "flux.hpp"
+#include "ggml_extend.hpp"
+#include "mmdit.hpp"
+
+// Ref: https://github.com/Alpha-VLLM/Lumina-Image-2.0/blob/main/models/model.py
+// Ref: https://github.com/huggingface/diffusers/pull/12703
+
+#ifndef MIN
+#define MIN(a, b) ((a) < (b) ? (a) : (b))
+#endif
+
+namespace ZImage {
+    constexpr int Z_IMAGE_GRAPH_SIZE = 20480;
+    constexpr int ADALN_EMBED_DIM    = 256;
+    constexpr int SEQ_MULTI_OF       = 32;
+
+    struct JointAttention : public GGMLBlock {
+    protected:
+        int64_t head_dim;
+        int64_t num_heads;
+        int64_t num_kv_heads;
+        bool qk_norm;
+
+    public:
+        JointAttention(int64_t hidden_size, int64_t head_dim, int64_t num_heads, int64_t num_kv_heads, bool qk_norm)
+            : head_dim(head_dim), num_heads(num_heads), num_kv_heads(num_kv_heads), qk_norm(qk_norm) {
+            blocks["qkv"] = std::make_shared<Linear>(hidden_size, (num_heads + num_kv_heads * 2) * head_dim, false);
+            blocks["out"] = std::make_shared<Linear>(num_heads * head_dim, hidden_size, false);
+            if (qk_norm) {
+                blocks["q_norm"] = std::make_shared<RMSNorm>(head_dim);
+                blocks["k_norm"] = std::make_shared<RMSNorm>(head_dim);
+            }
+        }
+
+        struct ggml_tensor* forward(GGMLRunnerContext* ctx,
+                                    struct ggml_tensor* x,
+                                    struct ggml_tensor* pe,
+                                    struct ggml_tensor* mask = nullptr) {
+            // x: [N, n_token, hidden_size]
+            int64_t n_token = x->ne[1];
+            int64_t N       = x->ne[2];
+            auto qkv_proj   = std::dynamic_pointer_cast<Linear>(blocks["qkv"]);
+            auto out_proj   = std::dynamic_pointer_cast<Linear>(blocks["out"]);
+
+            auto qkv = qkv_proj->forward(ctx, x);                                                                            // [N, n_token, (num_heads + num_kv_heads*2)*head_dim]
+            qkv      = ggml_reshape_4d(ctx->ggml_ctx, qkv, head_dim, num_heads + num_kv_heads * 2, qkv->ne[1], qkv->ne[2]);  // [N, n_token, num_heads + num_kv_heads*2, head_dim]
+            qkv      = ggml_cont(ctx->ggml_ctx, ggml_ext_torch_permute(ctx->ggml_ctx, qkv, 0, 2, 3, 1));                     // [num_heads + num_kv_heads*2, N, n_token, head_dim]
+
+            auto q = ggml_view_4d(ctx->ggml_ctx, qkv, qkv->ne[0], qkv->ne[1], qkv->ne[2], num_heads, qkv->nb[1], qkv->nb[2], qkv->nb[3], 0);                                           // [num_heads, N, n_token, head_dim]
+            auto k = ggml_view_4d(ctx->ggml_ctx, qkv, qkv->ne[0], qkv->ne[1], qkv->ne[2], num_kv_heads, qkv->nb[1], qkv->nb[2], qkv->nb[3], qkv->nb[3] * num_heads);                   // [num_kv_heads, N, n_token, head_dim]
+            auto v = ggml_view_4d(ctx->ggml_ctx, qkv, qkv->ne[0], qkv->ne[1], qkv->ne[2], num_kv_heads, qkv->nb[1], qkv->nb[2], qkv->nb[3], qkv->nb[3] * (num_heads + num_kv_heads));  // [num_kv_heads, N, n_token, head_dim]
+
+            q = ggml_cont(ctx->ggml_ctx, ggml_ext_torch_permute(ctx->ggml_ctx, q, 0, 3, 1, 2));  // [N, n_token, num_heads, head_dim]
+            k = ggml_cont(ctx->ggml_ctx, ggml_ext_torch_permute(ctx->ggml_ctx, k, 0, 3, 1, 2));  // [N, n_token, num_kv_heads, head_dim]
+            v = ggml_cont(ctx->ggml_ctx, ggml_ext_torch_permute(ctx->ggml_ctx, v, 0, 3, 1, 2));  // [N, n_token, num_kv_heads, head_dim]
+
+            if (qk_norm) {
+                auto q_norm = std::dynamic_pointer_cast<RMSNorm>(blocks["q_norm"]);
+                auto k_norm = std::dynamic_pointer_cast<RMSNorm>(blocks["k_norm"]);
+
+                q = q_norm->forward(ctx, q);
+                k = k_norm->forward(ctx, k);
+            }
+
+            x = Rope::attention(ctx, q, k, v, pe, mask, 1.f / 128.f);  // [N, n_token, num_heads * head_dim]
+
+            x = out_proj->forward(ctx, x);  // [N, n_token, hidden_size]
+            return x;
+        }
+    };
+
+    class FeedForward : public GGMLBlock {
+    public:
+        FeedForward(int64_t dim,
+                    int64_t hidden_dim,
+                    int64_t multiple_of,
+                    float ffn_dim_multiplier = 0.f) {
+            if (ffn_dim_multiplier > 0.f) {
+                hidden_dim = static_cast<int64_t>(ffn_dim_multiplier * hidden_dim);
+            }
+            hidden_dim   = multiple_of * ((hidden_dim + multiple_of - 1) / multiple_of);
+            blocks["w1"] = std::make_shared<Linear>(dim, hidden_dim, false);
+
+            bool force_prec_f32 = false;
+            float scale         = 1.f / 128.f;
+#ifdef SD_USE_VULKAN
+            force_prec_f32 = true;
+#endif
+            // The purpose of the scale here is to prevent NaN issues in certain situations.
+            // For example, when using CUDA but the weights are k-quants.
+            blocks["w2"] = std::make_shared<Linear>(hidden_dim, dim, false, false, force_prec_f32, 1.f / 128.f);
+            blocks["w3"] = std::make_shared<Linear>(dim, hidden_dim, false);
+        }
+
+        struct ggml_tensor* forward(GGMLRunnerContext* ctx, struct ggml_tensor* x) {
+            auto w1 = std::dynamic_pointer_cast<Linear>(blocks["w1"]);
+            auto w2 = std::dynamic_pointer_cast<Linear>(blocks["w2"]);
+            auto w3 = std::dynamic_pointer_cast<Linear>(blocks["w3"]);
+
+            auto x1 = w1->forward(ctx, x);
+            auto x3 = w3->forward(ctx, x);
+            x       = ggml_mul(ctx->ggml_ctx, ggml_silu(ctx->ggml_ctx, x1), x3);
+            x       = w2->forward(ctx, x);
+
+            return x;
+        }
+    };
+
+    __STATIC_INLINE__ struct ggml_tensor* modulate(struct ggml_context* ctx,
+                                                   struct ggml_tensor* x,
+                                                   struct ggml_tensor* scale) {
+        // x: [N, L, C]
+        // scale: [N, C]
+        scale = ggml_reshape_3d(ctx, scale, scale->ne[0], 1, scale->ne[1]);  // [N, 1, C]
+        x     = ggml_add(ctx, x, ggml_mul(ctx, x, scale));
+        return x;
+    }
+
+    struct JointTransformerBlock : public GGMLBlock {
+    protected:
+        bool modulation;
+
+    public:
+        JointTransformerBlock(int layer_id,
+                              int64_t hidden_size,
+                              int64_t head_dim,
+                              int64_t num_heads,
+                              int64_t num_kv_heads,
+                              int64_t multiple_of,
+                              float ffn_dim_multiplier,
+                              float norm_eps,
+                              bool qk_norm,
+                              bool modulation = true)
+            : modulation(modulation) {
+            blocks["attention"]       = std::make_shared<JointAttention>(hidden_size, head_dim, num_heads, num_kv_heads, qk_norm);
+            blocks["feed_forward"]    = std::make_shared<FeedForward>(hidden_size, hidden_size, multiple_of, ffn_dim_multiplier);
+            blocks["attention_norm1"] = std::make_shared<RMSNorm>(hidden_size, norm_eps);
+            blocks["ffn_norm1"]       = std::make_shared<RMSNorm>(hidden_size, norm_eps);
+            blocks["attention_norm2"] = std::make_shared<RMSNorm>(hidden_size, norm_eps);
+            blocks["ffn_norm2"]       = std::make_shared<RMSNorm>(hidden_size, norm_eps);
+            if (modulation) {
+                blocks["adaLN_modulation.0"] = std::make_shared<Linear>(MIN(hidden_size, ADALN_EMBED_DIM), 4 * hidden_size);
+            }
+        }
+
+        struct ggml_tensor* forward(GGMLRunnerContext* ctx,
+                                    struct ggml_tensor* x,
+                                    struct ggml_tensor* pe,
+                                    struct ggml_tensor* mask        = nullptr,
+                                    struct ggml_tensor* adaln_input = nullptr) {
+            auto attention       = std::dynamic_pointer_cast<JointAttention>(blocks["attention"]);
+            auto feed_forward    = std::dynamic_pointer_cast<FeedForward>(blocks["feed_forward"]);
+            auto attention_norm1 = std::dynamic_pointer_cast<RMSNorm>(blocks["attention_norm1"]);
+            auto ffn_norm1       = std::dynamic_pointer_cast<RMSNorm>(blocks["ffn_norm1"]);
+            auto attention_norm2 = std::dynamic_pointer_cast<RMSNorm>(blocks["attention_norm2"]);
+            auto ffn_norm2       = std::dynamic_pointer_cast<RMSNorm>(blocks["ffn_norm2"]);
+
+            if (modulation) {
+                GGML_ASSERT(adaln_input != nullptr);
+                auto adaLN_modulation_0 = std::dynamic_pointer_cast<Linear>(blocks["adaLN_modulation.0"]);
+
+                auto m         = adaLN_modulation_0->forward(ctx, adaln_input);  // [N, 4 * hidden_size]
+                auto mods      = ggml_ext_chunk(ctx->ggml_ctx, m, 4, 0);
+                auto scale_msa = mods[0];
+                auto gate_msa  = mods[1];
+                auto scale_mlp = mods[2];
+                auto gate_mlp  = mods[3];
+
+                auto residual = x;
+                x             = modulate(ctx->ggml_ctx, attention_norm1->forward(ctx, x), scale_msa);
+                x             = attention->forward(ctx, x, pe, mask);
+                x             = attention_norm2->forward(ctx, x);
+                x             = ggml_mul(ctx->ggml_ctx, x, ggml_tanh(ctx->ggml_ctx, gate_msa));
+                x             = ggml_add(ctx->ggml_ctx, x, residual);
+
+                residual = x;
+                x        = modulate(ctx->ggml_ctx, ffn_norm1->forward(ctx, x), scale_mlp);
+                x        = feed_forward->forward(ctx, x);
+                x        = ffn_norm2->forward(ctx, x);
+                x        = ggml_mul(ctx->ggml_ctx, x, ggml_tanh(ctx->ggml_ctx, gate_mlp));
+                x        = ggml_add(ctx->ggml_ctx, x, residual);
+            } else {
+                GGML_ASSERT(adaln_input == nullptr);
+
+                auto residual = x;
+                x             = attention_norm1->forward(ctx, x);
+                x             = attention->forward(ctx, x, pe, mask);
+                x             = attention_norm2->forward(ctx, x);
+                x             = ggml_add(ctx->ggml_ctx, x, residual);
+
+                residual = x;
+                x        = ffn_norm1->forward(ctx, x);
+                x        = feed_forward->forward(ctx, x);
+                x        = ffn_norm2->forward(ctx, x);
+                x        = ggml_add(ctx->ggml_ctx, x, residual);
+            }
+
+            return x;
+        }
+    };
+
+    struct FinalLayer : public GGMLBlock {
+    public:
+        FinalLayer(int64_t hidden_size,
+                   int64_t patch_size,
+                   int64_t out_channels) {
+            blocks["norm_final"]         = std::make_shared<LayerNorm>(hidden_size, 1e-06f, false);
+            blocks["linear"]             = std::make_shared<Linear>(hidden_size, patch_size * patch_size * out_channels, true, true);
+            blocks["adaLN_modulation.1"] = std::make_shared<Linear>(MIN(hidden_size, ADALN_EMBED_DIM), hidden_size);
+        }
+
+        struct ggml_tensor* forward(GGMLRunnerContext* ctx,
+                                    struct ggml_tensor* x,
+                                    struct ggml_tensor* c) {
+            // x: [N, n_token, hidden_size]
+            // c: [N, hidden_size]
+            // return: [N, n_token, patch_size * patch_size * out_channels]
+            auto norm_final         = std::dynamic_pointer_cast<LayerNorm>(blocks["norm_final"]);
+            auto linear             = std::dynamic_pointer_cast<Linear>(blocks["linear"]);
+            auto adaLN_modulation_1 = std::dynamic_pointer_cast<Linear>(blocks["adaLN_modulation.1"]);
+
+            auto scale = adaLN_modulation_1->forward(ctx, ggml_silu(ctx->ggml_ctx, c));  // [N, hidden_size]
+            x          = norm_final->forward(ctx, x);
+            x          = modulate(ctx->ggml_ctx, x, scale);
+            x          = linear->forward(ctx, x);
+
+            return x;
+        }
+    };
+
+    struct ZImageParams {
+        int64_t patch_size         = 2;
+        int64_t hidden_size        = 3840;
+        int64_t in_channels        = 16;
+        int64_t out_channels       = 16;
+        int64_t num_layers         = 30;
+        int64_t num_refiner_layers = 2;
+        int64_t head_dim           = 128;
+        int64_t num_heads          = 30;
+        int64_t num_kv_heads       = 30;
+        int64_t multiple_of        = 256;
+        float ffn_dim_multiplier   = 8.0 / 3.0f;
+        float norm_eps             = 1e-5f;
+        bool qk_norm               = true;
+        int64_t cap_feat_dim       = 2560;
+        float theta                = 256.f;
+        std::vector<int> axes_dim  = {32, 48, 48};
+        int64_t axes_dim_sum       = 128;
+    };
+
+    class ZImageModel : public GGMLBlock {
+    protected:
+        ZImageParams z_image_params;
+
+        void init_params(struct ggml_context* ctx, const String2TensorStorage& tensor_storage_map = {}, const std::string prefix = "") override {
+            params["cap_pad_token"] = ggml_new_tensor_1d(ctx, GGML_TYPE_F32, z_image_params.hidden_size);
+            params["x_pad_token"]   = ggml_new_tensor_1d(ctx, GGML_TYPE_F32, z_image_params.hidden_size);
+        }
+
+    public:
+        ZImageModel() = default;
+        ZImageModel(ZImageParams z_image_params)
+            : z_image_params(z_image_params) {
+            blocks["x_embedder"]     = std::make_shared<Linear>(z_image_params.patch_size * z_image_params.patch_size * z_image_params.in_channels, z_image_params.hidden_size);
+            blocks["t_embedder"]     = std::make_shared<TimestepEmbedder>(MIN(z_image_params.hidden_size, 1024), 256, 256);
+            blocks["cap_embedder.0"] = std::make_shared<RMSNorm>(z_image_params.cap_feat_dim, z_image_params.norm_eps);
+            blocks["cap_embedder.1"] = std::make_shared<Linear>(z_image_params.cap_feat_dim, z_image_params.hidden_size);
+
+            for (int i = 0; i < z_image_params.num_refiner_layers; i++) {
+                auto block = std::make_shared<JointTransformerBlock>(i,
+                                                                     z_image_params.hidden_size,
+                                                                     z_image_params.head_dim,
+                                                                     z_image_params.num_heads,
+                                                                     z_image_params.num_kv_heads,
+                                                                     z_image_params.multiple_of,
+                                                                     z_image_params.ffn_dim_multiplier,
+                                                                     z_image_params.norm_eps,
+                                                                     z_image_params.qk_norm,
+                                                                     true);
+
+                blocks["noise_refiner." + std::to_string(i)] = block;
+            }
+
+            for (int i = 0; i < z_image_params.num_refiner_layers; i++) {
+                auto block = std::make_shared<JointTransformerBlock>(i,
+                                                                     z_image_params.hidden_size,
+                                                                     z_image_params.head_dim,
+                                                                     z_image_params.num_heads,
+                                                                     z_image_params.num_kv_heads,
+                                                                     z_image_params.multiple_of,
+                                                                     z_image_params.ffn_dim_multiplier,
+                                                                     z_image_params.norm_eps,
+                                                                     z_image_params.qk_norm,
+                                                                     false);
+
+                blocks["context_refiner." + std::to_string(i)] = block;
+            }
+
+            for (int i = 0; i < z_image_params.num_layers; i++) {
+                auto block = std::make_shared<JointTransformerBlock>(i,
+                                                                     z_image_params.hidden_size,
+                                                                     z_image_params.head_dim,
+                                                                     z_image_params.num_heads,
+                                                                     z_image_params.num_kv_heads,
+                                                                     z_image_params.multiple_of,
+                                                                     z_image_params.ffn_dim_multiplier,
+                                                                     z_image_params.norm_eps,
+                                                                     z_image_params.qk_norm,
+                                                                     true);
+
+                blocks["layers." + std::to_string(i)] = block;
+            }
+
+            blocks["final_layer"] = std::make_shared<FinalLayer>(z_image_params.hidden_size, z_image_params.patch_size, z_image_params.out_channels);
+        }
+
+        struct ggml_tensor* pad_to_patch_size(struct ggml_context* ctx,
+                                              struct ggml_tensor* x) {
+            int64_t W = x->ne[0];
+            int64_t H = x->ne[1];
+
+            int pad_h = (z_image_params.patch_size - H % z_image_params.patch_size) % z_image_params.patch_size;
+            int pad_w = (z_image_params.patch_size - W % z_image_params.patch_size) % z_image_params.patch_size;
+            x         = ggml_pad(ctx, x, pad_w, pad_h, 0, 0);  // [N, C, H + pad_h, W + pad_w]
+            return x;
+        }
+
+        struct ggml_tensor* patchify(struct ggml_context* ctx,
+                                     struct ggml_tensor* x) {
+            // x: [N, C, H, W]
+            // return: [N, h*w, patch_size*patch_size*C]
+            int64_t N = x->ne[3];
+            int64_t C = x->ne[2];
+            int64_t H = x->ne[1];
+            int64_t W = x->ne[0];
+            int64_t p = z_image_params.patch_size;
+            int64_t h = H / z_image_params.patch_size;
+            int64_t w = W / z_image_params.patch_size;
+
+            GGML_ASSERT(h * p == H && w * p == W);
+
+            x = ggml_reshape_4d(ctx, x, p, w, p, h * C * N);                 // [N*C*h, p, w, p]
+            x = ggml_cont(ctx, ggml_permute(ctx, x, 0, 2, 1, 3));            // [N*C*h, w, p, p]
+            x = ggml_reshape_4d(ctx, x, p * p, w * h, C, N);                 // [N, C, h*w, p*p]
+            x = ggml_cont(ctx, ggml_ext_torch_permute(ctx, x, 2, 0, 1, 3));  // [N, h*w, C, p*p]
+            x = ggml_reshape_3d(ctx, x, C * p * p, w * h, N);                // [N, h*w, p*p*C]
+            return x;
+        }
+
+        struct ggml_tensor* process_img(struct ggml_context* ctx,
+                                        struct ggml_tensor* x) {
+            x = pad_to_patch_size(ctx, x);
+            x = patchify(ctx, x);
+            return x;
+        }
+
+        struct ggml_tensor* unpatchify(struct ggml_context* ctx,
+                                       struct ggml_tensor* x,
+                                       int64_t h,
+                                       int64_t w) {
+            // x: [N, h*w, patch_size*patch_size*C]
+            // return: [N, C, H, W]
+            int64_t N = x->ne[2];
+            int64_t C = x->ne[0] / z_image_params.patch_size / z_image_params.patch_size;
+            int64_t H = h * z_image_params.patch_size;
+            int64_t W = w * z_image_params.patch_size;
+            int64_t p = z_image_params.patch_size;
+
+            GGML_ASSERT(C * p * p == x->ne[0]);
+
+            x = ggml_reshape_4d(ctx, x, C, p * p, w * h, N);                 // [N, h*w, p*p, C]
+            x = ggml_cont(ctx, ggml_ext_torch_permute(ctx, x, 1, 2, 0, 3));  // [N, C, h*w, p*p]
+            x = ggml_reshape_4d(ctx, x, p, p, w, h * C * N);                 // [N*C*h, w, p, p]
+            x = ggml_cont(ctx, ggml_permute(ctx, x, 0, 2, 1, 3));            // [N*C*h, p, w, p]
+            x = ggml_reshape_4d(ctx, x, W, H, C, N);                         // [N, C, h*p, w*p]
+
+            return x;
+        }
+
+        struct ggml_tensor* forward_core(GGMLRunnerContext* ctx,
+                                         struct ggml_tensor* x,
+                                         struct ggml_tensor* timestep,
+                                         struct ggml_tensor* context,
+                                         struct ggml_tensor* pe) {
+            auto x_embedder     = std::dynamic_pointer_cast<Linear>(blocks["x_embedder"]);
+            auto t_embedder     = std::dynamic_pointer_cast<TimestepEmbedder>(blocks["t_embedder"]);
+            auto cap_embedder_0 = std::dynamic_pointer_cast<RMSNorm>(blocks["cap_embedder.0"]);
+            auto cap_embedder_1 = std::dynamic_pointer_cast<Linear>(blocks["cap_embedder.1"]);
+            auto norm_final     = std::dynamic_pointer_cast<RMSNorm>(blocks["norm_final"]);
+            auto final_layer    = std::dynamic_pointer_cast<FinalLayer>(blocks["final_layer"]);
+
+            auto txt_pad_token = params["cap_pad_token"];
+            auto img_pad_token = params["x_pad_token"];
+
+            int64_t N           = x->ne[2];
+            int64_t n_img_token = x->ne[1];
+            int64_t n_txt_token = context->ne[1];
+
+            auto t_emb = t_embedder->forward(ctx, timestep);
+
+            auto txt = cap_embedder_1->forward(ctx, cap_embedder_0->forward(ctx, context));  // [N, n_txt_token, hidden_size]
+            auto img = x_embedder->forward(ctx, x);                                          // [N, n_img_token, hidden_size]
+
+            int64_t n_txt_pad_token = Rope::bound_mod(n_txt_token, SEQ_MULTI_OF);
+            if (n_txt_pad_token > 0) {
+                auto txt_pad_tokens = ggml_repeat_4d(ctx->ggml_ctx, txt_pad_token, txt_pad_token->ne[0], n_txt_pad_token, N, 1);
+                txt                 = ggml_concat(ctx->ggml_ctx, txt, txt_pad_tokens, 1);  // [N, n_txt_token + n_txt_pad_token, hidden_size]
+            }
+
+            int64_t n_img_pad_token = Rope::bound_mod(n_img_token, SEQ_MULTI_OF);
+            if (n_img_pad_token > 0) {
+                auto img_pad_tokens = ggml_repeat_4d(ctx->ggml_ctx, img_pad_token, img_pad_token->ne[0], n_img_pad_token, N, 1);
+                img                 = ggml_concat(ctx->ggml_ctx, img, img_pad_tokens, 1);  // [N, n_img_token + n_img_pad_token, hidden_size]
+            }
+
+            GGML_ASSERT(txt->ne[1] + img->ne[1] == pe->ne[3]);
+
+            auto txt_pe = ggml_ext_slice(ctx->ggml_ctx, pe, 3, 0, txt->ne[1]);
+            auto img_pe = ggml_ext_slice(ctx->ggml_ctx, pe, 3, txt->ne[1], pe->ne[3]);
+
+            for (int i = 0; i < z_image_params.num_refiner_layers; i++) {
+                auto block = std::dynamic_pointer_cast<JointTransformerBlock>(blocks["context_refiner." + std::to_string(i)]);
+
+                txt = block->forward(ctx, txt, txt_pe, nullptr, nullptr);
+            }
+
+            for (int i = 0; i < z_image_params.num_refiner_layers; i++) {
+                auto block = std::dynamic_pointer_cast<JointTransformerBlock>(blocks["noise_refiner." + std::to_string(i)]);
+
+                img = block->forward(ctx, img, img_pe, nullptr, t_emb);
+            }
+
+            auto txt_img = ggml_concat(ctx->ggml_ctx, txt, img, 1);  // [N, n_txt_token + n_txt_pad_token + n_img_token + n_img_pad_token, hidden_size]
+
+            for (int i = 0; i < z_image_params.num_layers; i++) {
+                auto block = std::dynamic_pointer_cast<JointTransformerBlock>(blocks["layers." + std::to_string(i)]);
+
+                txt_img = block->forward(ctx, txt_img, pe, nullptr, t_emb);
+            }
+
+            txt_img = final_layer->forward(ctx, txt_img, t_emb);  // [N, n_txt_token + n_txt_pad_token + n_img_token + n_img_pad_token, ph*pw*C]
+
+            img = ggml_ext_slice(ctx->ggml_ctx, txt_img, 1, n_txt_token + n_txt_pad_token, n_txt_token + n_txt_pad_token + n_img_token);  // [N, n_img_token, ph*pw*C]
+
+            return img;
+        }
+
+        struct ggml_tensor* forward(GGMLRunnerContext* ctx,
+                                    struct ggml_tensor* x,
+                                    struct ggml_tensor* timestep,
+                                    struct ggml_tensor* context,
+                                    struct ggml_tensor* pe,
+                                    std::vector<ggml_tensor*> ref_latents = {}) {
+            // Forward pass of DiT.
+            // x: [N, C, H, W]
+            // timestep: [N,]
+            // context: [N, L, D]
+            // pe: [L, d_head/2, 2, 2]
+            // return: [N, C, H, W]
+
+            int64_t W = x->ne[0];
+            int64_t H = x->ne[1];
+            int64_t C = x->ne[2];
+            int64_t N = x->ne[3];
+
+            auto img             = process_img(ctx->ggml_ctx, x);
+            uint64_t n_img_token = img->ne[1];
+
+            if (ref_latents.size() > 0) {
+                for (ggml_tensor* ref : ref_latents) {
+                    ref = process_img(ctx->ggml_ctx, ref);
+                    img = ggml_concat(ctx->ggml_ctx, img, ref, 1);
+                }
+            }
+
+            int64_t h_len = ((H + (z_image_params.patch_size / 2)) / z_image_params.patch_size);
+            int64_t w_len = ((W + (z_image_params.patch_size / 2)) / z_image_params.patch_size);
+
+            auto out = forward_core(ctx, img, timestep, context, pe);
+
+            out = ggml_ext_slice(ctx->ggml_ctx, out, 1, 0, n_img_token);  // [N, n_img_token, ph*pw*C]
+            out = unpatchify(ctx->ggml_ctx, out, h_len, w_len);           // [N, C, H + pad_h, W + pad_w]
+
+            // slice
+            out = ggml_ext_slice(ctx->ggml_ctx, out, 1, 0, H);  // [N, C, H, W + pad_w]
+            out = ggml_ext_slice(ctx->ggml_ctx, out, 0, 0, W);  // [N, C, H, W]
+
+            out = ggml_scale(ctx->ggml_ctx, out, -1.f);
+
+            return out;
+        }
+    };
+
+    struct ZImageRunner : public GGMLRunner {
+    public:
+        ZImageParams z_image_params;
+        ZImageModel z_image;
+        std::vector<float> pe_vec;
+        std::vector<float> timestep_vec;
+        SDVersion version;
+
+        ZImageRunner(ggml_backend_t backend,
+                     bool offload_params_to_cpu,
+                     const String2TensorStorage& tensor_storage_map = {},
+                     const std::string prefix                       = "",
+                     SDVersion version                              = VERSION_Z_IMAGE)
+            : GGMLRunner(backend, offload_params_to_cpu) {
+            z_image = ZImageModel(z_image_params);
+            z_image.init(params_ctx, tensor_storage_map, prefix);
+        }
+
+        std::string get_desc() override {
+            return "z_image";
+        }
+
+        void get_param_tensors(std::map<std::string, struct ggml_tensor*>& tensors, const std::string prefix) {
+            z_image.get_param_tensors(tensors, prefix);
+        }
+
+        struct ggml_cgraph* build_graph(struct ggml_tensor* x,
+                                        struct ggml_tensor* timesteps,
+                                        struct ggml_tensor* context,
+                                        std::vector<ggml_tensor*> ref_latents = {},
+                                        bool increase_ref_index               = false) {
+            GGML_ASSERT(x->ne[3] == 1);
+            struct ggml_cgraph* gf = new_graph_custom(Z_IMAGE_GRAPH_SIZE);
+
+            x         = to_backend(x);
+            context   = to_backend(context);
+            timesteps = to_backend(timesteps);
+
+            for (int i = 0; i < ref_latents.size(); i++) {
+                ref_latents[i] = to_backend(ref_latents[i]);
+            }
+
+            pe_vec      = Rope::gen_z_image_pe(x->ne[1],
+                                               x->ne[0],
+                                               z_image_params.patch_size,
+                                               x->ne[3],
+                                               context->ne[1],
+                                               SEQ_MULTI_OF,
+                                               ref_latents,
+                                               increase_ref_index,
+                                               z_image_params.theta,
+                                               z_image_params.axes_dim);
+            int pos_len = pe_vec.size() / z_image_params.axes_dim_sum / 2;
+            // LOG_DEBUG("pos_len %d", pos_len);
+            auto pe = ggml_new_tensor_4d(compute_ctx, GGML_TYPE_F32, 2, 2, z_image_params.axes_dim_sum / 2, pos_len);
+            // pe->data = pe_vec.data();
+            // print_ggml_tensor(pe, true, "pe");
+            // pe->data = nullptr;
+            set_backend_tensor_data(pe, pe_vec.data());
+            auto runner_ctx = get_context();
+
+            struct ggml_tensor* out = z_image.forward(&runner_ctx,
+                                                      x,
+                                                      timesteps,
+                                                      context,
+                                                      pe,
+                                                      ref_latents);
+
+            ggml_build_forward_expand(gf, out);
+
+            return gf;
+        }
+
+        void compute(int n_threads,
+                     struct ggml_tensor* x,
+                     struct ggml_tensor* timesteps,
+                     struct ggml_tensor* context,
+                     std::vector<ggml_tensor*> ref_latents = {},
+                     bool increase_ref_index               = false,
+                     struct ggml_tensor** output           = nullptr,
+                     struct ggml_context* output_ctx       = nullptr) {
+            // x: [N, in_channels, h, w]
+            // timesteps: [N, ]
+            // context: [N, max_position, hidden_size]
+            auto get_graph = [&]() -> struct ggml_cgraph* {
+                return build_graph(x, timesteps, context, ref_latents, increase_ref_index);
+            };
+
+            GGMLRunner::compute(get_graph, n_threads, false, output, output_ctx);
+        }
+
+        void test() {
+            struct ggml_init_params params;
+            params.mem_size   = static_cast<size_t>(1024 * 1024) * 1024;  // 1GB
+            params.mem_buffer = nullptr;
+            params.no_alloc   = false;
+
+            struct ggml_context* work_ctx = ggml_init(params);
+            GGML_ASSERT(work_ctx != nullptr);
+
+            {
+                // auto x = ggml_new_tensor_4d(work_ctx, GGML_TYPE_F32, 16, 16, 16, 1);
+                // ggml_set_f32(x, 0.01f);
+                auto x = load_tensor_from_file(work_ctx, "./z_image_x.bin");
+                print_ggml_tensor(x);
+
+                std::vector<float> timesteps_vec(1, 0.f);
+                auto timesteps = vector_to_ggml_tensor(work_ctx, timesteps_vec);
+
+                // auto context = ggml_new_tensor_3d(work_ctx, GGML_TYPE_F32, 2560, 256, 1);
+                // ggml_set_f32(context, 0.01f);
+                auto context = load_tensor_from_file(work_ctx, "./z_image_context.bin");
+                print_ggml_tensor(context);
+
+                struct ggml_tensor* out = nullptr;
+
+                int t0 = ggml_time_ms();
+                compute(8, x, timesteps, context, {}, false, &out, work_ctx);
+                int t1 = ggml_time_ms();
+
+                print_ggml_tensor(out);
+                LOG_DEBUG("z_image test done in %dms", t1 - t0);
+            }
+        }
+
+        static void load_from_file_and_test(const std::string& file_path) {
+            // cuda q8: pass
+            // cuda q8 fa: pass
+            // ggml_backend_t backend = ggml_backend_cuda_init(0);
+            ggml_backend_t backend    = ggml_backend_cpu_init();
+            ggml_type model_data_type = GGML_TYPE_Q8_0;
+
+            ModelLoader model_loader;
+            if (!model_loader.init_from_file_and_convert_name(file_path, "model.diffusion_model.")) {
+                LOG_ERROR("init model loader from file failed: '%s'", file_path.c_str());
+                return;
+            }
+
+            auto& tensor_storage_map = model_loader.get_tensor_storage_map();
+            if (model_data_type != GGML_TYPE_COUNT) {
+                for (auto& [name, tensor_storage] : tensor_storage_map) {
+                    if (ends_with(name, "weight")) {
+                        tensor_storage.expected_type = model_data_type;
+                    }
+                }
+            }
+
+            std::shared_ptr<ZImageRunner> z_image = std::make_shared<ZImageRunner>(backend,
+                                                                                   false,
+                                                                                   tensor_storage_map,
+                                                                                   "model.diffusion_model",
+                                                                                   VERSION_QWEN_IMAGE);
+
+            z_image->alloc_params_buffer();
+            std::map<std::string, ggml_tensor*> tensors;
+            z_image->get_param_tensors(tensors, "model.diffusion_model");
+
+            bool success = model_loader.load_tensors(tensors);
+
+            if (!success) {
+                LOG_ERROR("load tensors from model loader failed");
+                return;
+            }
+
+            LOG_INFO("z_image model loaded");
+            z_image->test();
+        }
+    };
+
+}  // namespace ZImage
+
+#endif  // __Z_IMAGE_HPP__