/// <summary>
/// Applies color filter to image.
/// (Safer if source image was compressed, may be additional bytes per row)
/// </summary>
/// <param name="imageBytes">Color image bytes to process</param>
/// <param name="r">Red component to apply</param>
/// <param name="g">Green component to apply</param>
/// <param name="b">Blue component to apply</param>
/// <param name="bmpData">Image dimension info</param>
public static void ApplyFilterDirectRGB(byte[] imageBytes, byte r, byte g, byte b, BitmapData bmpData)
{
if (!bmpData.IsColor())
{
throw new ArgumentException("Image is not color, RGB filter cannot be applied.");
}
int stride = bmpData.Stride;
int stridePadding = bmpData.GetStridePaddingLength();
int width = stride - stridePadding;
int height = bmpData.Height;
int limit = bmpData.GetSafeArrayLimitForImage(imageBytes);
// May also have alpha byte
int pixelDepth = bmpData.GetPixelDepth();
// Apply mask for each color pixel
for (int y = 0; y < height; y++)
{
// Images may have extra bytes per row to pad for CPU addressing.
// so need to ensure we traverse to the correct byte when moving between rows.
// I.e. not divisible by 3
int offset = y * stride;
for (int x = 0; x < width; x += pixelDepth)
{
int i = offset + x;
if (i < limit)
{
// Red (LSB)
imageBytes[i + 2] &= r;
// Green
imageBytes[i + 1] &= g;
// Blue (MSB)
imageBytes[i] &= b;
}
}
}
}
/// <summary>
/// Gets the stride value for image adjusted for any stride padding.
/// </summary>
public static int GetStrideWithoutPadding(this BitmapData bitmapData)
{
return(bitmapData.Stride - bitmapData.GetStridePaddingLength());
}
