private static IEnumerable<byte[]> indexedPixels(ImageBuffer image, Pixel[] lookups, int alphaThreshold, int maxColors, PaletteColorHistory[] paletteHistogram)
{
int pixelsCount = image.Image.Width * image.Image.Height;
var lineIndexes = new byte[(int)System.Math.Ceiling(image.Image.Width / System.Math.Log(256.0, maxColors))];
PaletteLookup lookup = new PaletteLookup(lookups);
--maxColors;
foreach (var pixelLine in image.PixelLines)
{
for (int pixelIndex = 0; pixelIndex < pixelLine.Length; pixelIndex++)
{
Pixel pixel = pixelLine[pixelIndex];
byte bestMatch = (byte)maxColors;
if (pixel.Alpha > alphaThreshold)
{
bestMatch = lookup.GetPaletteIndex(pixel);
paletteHistogram[bestMatch].AddPixel(pixel);
}
switch (maxColors)
{
case 256 - 1:
lineIndexes[pixelIndex] = bestMatch;
break;
case 16 - 1:
if (pixelIndex % 2 == 0) { lineIndexes[pixelIndex / 2] = (byte)(bestMatch << 4); }
else { lineIndexes[pixelIndex / 2] |= (byte)(bestMatch & 0x0F); }
break;
case 2 - 1:
if (pixelIndex % 8 == 0) { lineIndexes[pixelIndex / 8] = (byte)(bestMatch << 7); }
else { lineIndexes[pixelIndex / 8] |= (byte)((bestMatch & 0x01) << (7 - (pixelIndex % 8))); }
break;
}
}
yield return lineIndexes;
}
}
private static IEnumerable <byte[]> indexedPixels(ImageBuffer image, Pixel[] lookups, int alphaThreshold, int maxColors, PaletteColorHistory[] paletteHistogram)
{
int pixelsCount = image.Image.Width * image.Image.Height;
var lineIndexes = new byte[(int)System.Math.Ceiling(image.Image.Width / System.Math.Log(256.0, maxColors))];
PaletteLookup lookup = new PaletteLookup(lookups);
--maxColors;
foreach (var pixelLine in image.PixelLines)
{
for (int pixelIndex = 0; pixelIndex < pixelLine.Length; pixelIndex++)
{
Pixel pixel = pixelLine[pixelIndex];
byte bestMatch = (byte)maxColors;
if (pixel.Alpha > alphaThreshold)
{
bestMatch = lookup.GetPaletteIndex(pixel);
paletteHistogram[bestMatch].AddPixel(pixel);
}
switch (maxColors)
{
case 256 - 1:
lineIndexes[pixelIndex] = bestMatch;
break;
case 16 - 1:
if (pixelIndex % 2 == 0)
{
lineIndexes[pixelIndex / 2] = (byte)(bestMatch << 4);
}
else
{
lineIndexes[pixelIndex / 2] |= (byte)(bestMatch & 0x0F);
}
break;
case 2 - 1:
if (pixelIndex % 8 == 0)
{
lineIndexes[pixelIndex / 8] = (byte)(bestMatch << 7);
}
else
{
lineIndexes[pixelIndex / 8] |= (byte)((bestMatch & 0x01) << (7 - (pixelIndex % 8)));
}
break;
}
}
yield return(lineIndexes);
}
}
private static IEnumerable <byte[]> IndexedPixels(ImageBuffer image, Pixel[] lookups, int alphaThreshold, PaletteColorHistory[] paletteHistogram)
{
var lineIndexes = new byte[image.Image.Width];
var lookup = new PaletteLookup(lookups);
foreach (var pixelLine in image.PixelLines)
{
for (int pixelIndex = 0; pixelIndex < pixelLine.Length; pixelIndex++)
{
Pixel pixel = pixelLine[pixelIndex];
byte bestMatch = AlphaColor;
if (pixel.Alpha > alphaThreshold)
{
bestMatch = lookup.GetPaletteIndex(pixel);
paletteHistogram[bestMatch].AddPixel(pixel);
}
lineIndexes[pixelIndex] = bestMatch;
}
yield return(lineIndexes);
}
}
