private byte[] IndexPixels(List <Color> palette)
{
return(NonIndexedPixels.AsParallel().Select((x, i) => new { Index = i, Indexed = (byte)ColorExtensions.ClosestColorRgb(palette, x) }).Select(x => x.Indexed).ToArray());
#region Old code
//var pixels = new byte[NonIndexedPixels.Count];
//var pixelCount = 0;
//foreach (var color in NonIndexedPixels)
//{
// var index = palette.IndexOf(color);
// if (index == -1)
// {
// //Search for nearby colors.
// index = ColorExtensions.ClosestColorRgb(palette, color);
// //index = ColorExtensions.ClosestColorHue(palette, color);
// //index = ColorExtensions.ClosestColorRsb(palette, color);
// //Add colors to a dictionary, if available, no need to search.
// //TODO: Make this available for choice.
// }
// //Map the pixel to a color in the Color Table.
// pixels[pixelCount] = (byte)index;
// pixelCount++;
//}
//return pixels;
#endregion
}
private void GeneratePalette()
{
//TODO: more ways to decide which color to get
//Like removing similar colors (with less than 5% similarity) if there is more than 256 colors, etc.
//I probably can do that, using the groupby method.
ColorTable = NonIndexedPixels.AsParallel().GroupBy(x => x)
.OrderByDescending(g => g.Count()) //Order by most frequent values
.Select(g => g.FirstOrDefault()) //take the first among the group
.Take(MaximumNumberColor).ToList();
#region Handle transparency
//Make sure that the transparent color is added to list.
if (TransparentColor.HasValue && (!IsFirstFrame || UseGlobalColorTable) && ColorTable.Count == MaximumNumberColor)
{
//Only adds if there is MaximumNumberColor colors, so I need to make sure that the color won't be ignored.
//If there is less than MaximumNumberColor selected colors, it means that the transparent color is already selected.
//If the color isn't on the list, add or replace.
if (ColorTable.AsParallel().All(x => x != TransparentColor.Value))
{
//Adds to the last spot, keeping it sorted. (Since all the colors are ordered by descending)
ColorTable.Insert(MaximumNumberColor - 1, TransparentColor.Value);
//Remove the exceding value at the last position.
ColorTable.RemoveAt(MaximumNumberColor);
}
}
//I need to signal the other method that I won't need transparency.
WillUseTransparency = !IsFirstFrame && TransparentColor.HasValue && ColorTable.Contains(TransparentColor.Value);
#endregion
}
