236 lines
10 KiB
C#

namespace ScreenCapture.NET;
/// <summary>
/// Helper-class for black-bar removal.
/// </summary>
public static class BlackBarDetection
{
#region IImage
/// <summary>
/// Create an image with black bars removed
/// </summary>
/// <param name="image">The image the bars are removed from.</param>
/// <param name="threshold">The threshold of "blackness" used to detect black bars. (e. g. Threshold 5 will consider a pixel of color [5,5,5] as black.)</param>
/// <param name="removeTop">A bool indicating if black bars should be removed at the top of the image.</param>
/// <param name="removeBottom">A bool indicating if black bars should be removed at the bottom of the image.</param>
/// <param name="removeLeft">A bool indicating if black bars should be removed on the left side of the image.</param>
/// <param name="removeRight">A bool indicating if black bars should be removed on the right side of the image.</param>
/// <returns>The image with black bars removed.</returns>
public static IImage RemoveBlackBars(this IImage image, int threshold = 0, bool removeTop = true, bool removeBottom = true, bool removeLeft = true, bool removeRight = true)
{
int top = removeTop ? CalculateTop(image, threshold) : 0;
int bottom = removeBottom ? CalculateBottom(image, threshold) : image.Height;
int left = removeLeft ? CalculateLeft(image, threshold) : 0;
int right = removeRight ? CalculateRight(image, threshold) : image.Width;
return image[left, top, right - left, bottom - top];
}
/// <summary>
/// Calculates the first row starting from the top with at least one non black pixel.
/// </summary>
/// <param name="image">The image to check.</param>
/// <param name="threshold">The threshold of "blackness" used to detect black bars. (e. g. Threshold 5 will consider a pixel of color [5,5,5] as black.)</param>
/// <returns>The row number of the first row with at least one non-black pixel.</returns>
public static int CalculateTop(IImage image, int threshold)
{
IImage.IImageRows rows = image.Rows;
for (int y = 0; y < rows.Count; y++)
{
IImage.IImageRow row = rows[y];
foreach (IColor color in row)
{
if ((color.R > threshold) || (color.G > threshold) || (color.B > threshold))
return y;
}
}
return 0;
}
/// <summary>
/// Calculates the last row starting from the top with at least one non black pixel.
/// </summary>
/// <param name="image">The image to check.</param>
/// <param name="threshold">The threshold of "blackness" used to detect black bars. (e. g. Threshold 5 will consider a pixel of color [5,5,5] as black.)</param>
/// <returns>The row number of the last row with at least one non-black pixel.</returns>
public static int CalculateBottom(IImage image, int threshold)
{
IImage.IImageRows rows = image.Rows;
for (int y = rows.Count - 1; y >= 0; y--)
{
IImage.IImageRow row = rows[y];
foreach (IColor color in row)
{
if ((color.R > threshold) || (color.G > threshold) || (color.B > threshold))
return y;
}
}
return rows.Count;
}
/// <summary>
/// Calculates the first column starting from the left with at least one non black pixel.
/// </summary>
/// <param name="image">The image to check.</param>
/// <param name="threshold">The threshold of "blackness" used to detect black bars. (e. g. Threshold 5 will consider a pixel of color [5,5,5] as black.)</param>
/// <returns>The column number of the first column with at least one non-black pixel.</returns>
public static int CalculateLeft(IImage image, int threshold)
{
IImage.IImageColumns columns = image.Columns;
for (int x = 0; x < columns.Count; x++)
{
IImage.IImageColumn column = columns[x];
foreach (IColor color in column)
{
if ((color.R > threshold) || (color.G > threshold) || (color.B > threshold))
return x;
}
}
return 0;
}
/// <summary>
/// Calculates the last column starting from the top with at least one non black pixel.
/// </summary>
/// <param name="image">The image to check.</param>
/// <param name="threshold">The threshold of "blackness" used to detect black bars. (e. g. Threshold 5 will consider a pixel of color [5,5,5] as black.)</param>
/// <returns>The column number of the last column with at least one non-black pixel.</returns>
public static int CalculateRight(IImage image, int threshold)
{
IImage.IImageColumns columns = image.Columns;
for (int x = columns.Count - 1; x >= 0; x--)
{
IImage.IImageColumn column = columns[x];
foreach (IColor color in column)
{
if ((color.R > threshold) || (color.G > threshold) || (color.B > threshold))
return x;
}
}
return columns.Count;
}
#endregion
#region RefImage
/// <summary>
/// Create an image with black bars removed
/// </summary>
/// <param name="image">The image the bars are removed from.</param>
/// <param name="threshold">The threshold of "blackness" used to detect black bars. (e. g. Threshold 5 will consider a pixel of color [5,5,5] as black.)</param>
/// <param name="removeTop">A bool indicating if black bars should be removed at the top of the image.</param>
/// <param name="removeBottom">A bool indicating if black bars should be removed at the bottom of the image.</param>
/// <param name="removeLeft">A bool indicating if black bars should be removed on the left side of the image.</param>
/// <param name="removeRight">A bool indicating if black bars should be removed on the right side of the image.</param>
/// <returns>The image with black bars removed.</returns>
public static RefImage<TColor> RemoveBlackBars<TColor>(this RefImage<TColor> image, int threshold = 0, bool removeTop = true, bool removeBottom = true, bool removeLeft = true, bool removeRight = true)
where TColor : struct, IColor
{
int top = removeTop ? CalculateTop(image, threshold) : 0;
int bottom = removeBottom ? CalculateBottom(image, threshold) : image.Height - 1;
int left = removeLeft ? CalculateLeft(image, threshold) : 0;
int right = removeRight ? CalculateRight(image, threshold) : image.Width - 1;
return image[left, top, (right - left) + 1, (bottom - top) + 1];
}
/// <summary>
/// Calculates the first row starting from the top with at least one non black pixel.
/// </summary>
/// <param name="image">The image to check.</param>
/// <param name="threshold">The threshold of "blackness" used to detect black bars. (e. g. Threshold 5 will consider a pixel of color [5,5,5] as black.)</param>
/// <returns>The row number of the first row with at least one non-black pixel.</returns>
public static int CalculateTop<TColor>(this RefImage<TColor> image, int threshold)
where TColor : struct, IColor
{
RefImage<TColor>.ImageRows rows = image.Rows;
for (int y = 0; y < rows.Count; y++)
{
ReadOnlyRefEnumerable<TColor> row = rows[y];
foreach (TColor color in row)
{
if ((color.R > threshold) || (color.G > threshold) || (color.B > threshold))
return y;
}
}
return 0;
}
/// <summary>
/// Calculates the last row starting from the top with at least one non black pixel.
/// </summary>
/// <param name="image">The image to check.</param>
/// <param name="threshold">The threshold of "blackness" used to detect black bars. (e. g. Threshold 5 will consider a pixel of color [5,5,5] as black.)</param>
/// <returns>The row number of the last row with at least one non-black pixel.</returns>
public static int CalculateBottom<TColor>(this RefImage<TColor> image, int threshold)
where TColor : struct, IColor
{
RefImage<TColor>.ImageRows rows = image.Rows;
for (int y = rows.Count - 1; y >= 0; y--)
{
ReadOnlyRefEnumerable<TColor> row = rows[y];
foreach (TColor color in row)
{
if ((color.R > threshold) || (color.G > threshold) || (color.B > threshold))
return y;
}
}
return rows.Count;
}
/// <summary>
/// Calculates the first column starting from the left with at least one non black pixel.
/// </summary>
/// <param name="image">The image to check.</param>
/// <param name="threshold">The threshold of "blackness" used to detect black bars. (e. g. Threshold 5 will consider a pixel of color [5,5,5] as black.)</param>
/// <returns>The column number of the first column with at least one non-black pixel.</returns>
public static int CalculateLeft<TColor>(this RefImage<TColor> image, int threshold)
where TColor : struct, IColor
{
RefImage<TColor>.ImageColumns columns = image.Columns;
for (int x = 0; x < columns.Count; x++)
{
ReadOnlyRefEnumerable<TColor> column = columns[x];
foreach (TColor color in column)
{
if ((color.R > threshold) || (color.G > threshold) || (color.B > threshold))
return x;
}
}
return 0;
}
/// <summary>
/// Calculates the last column starting from the top with at least one non black pixel.
/// </summary>
/// <param name="image">The image to check.</param>
/// <param name="threshold">The threshold of "blackness" used to detect black bars. (e. g. Threshold 5 will consider a pixel of color [5,5,5] as black.)</param>
/// <returns>The column number of the last column with at least one non-black pixel.</returns>
public static int CalculateRight<TColor>(this RefImage<TColor> image, int threshold)
where TColor : struct, IColor
{
RefImage<TColor>.ImageColumns columns = image.Columns;
for (int x = columns.Count - 1; x >= 0; x--)
{
ReadOnlyRefEnumerable<TColor> column = columns[x];
foreach (TColor color in column)
{
if ((color.R > threshold) || (color.G > threshold) || (color.B > threshold))
return x;
}
}
return columns.Count;
}
#endregion
}