Modified the Quantizer to Xiaolin Wu's, updated the BitmapBuffer to support 8BPP but you still need to know what to call.... (needs some additional refactoring)

git-svn-id: http://svn.code.sf.net/p/greenshot/code/trunk@1712 7dccd23d-a4a3-4e1f-8c07-b4c1b4018ab4

GreenshotPlugin/Core/ImageHelper.cs

@@ -993,10 +993,61 @@ namespace GreenshotPlugin.Core {
 			return newImage;
 		}
 		
+		/// <summary>
+		/// Rotate the bitmap
+		/// </summary>
+		/// <param name="sourceBitmap"></param>
+		/// <param name="rotateFlipType"></param>
+		/// <returns></returns>
 		public static Bitmap RotateFlip(Bitmap sourceBitmap, RotateFlipType rotateFlipType) {
 			Bitmap returnBitmap = Clone(sourceBitmap);
 			returnBitmap.RotateFlip(rotateFlipType);
 			return returnBitmap;
 		}
+
+		/// <summary>
+		/// Get a quantizer, so we can check if it pays off to quantize
+		/// </summary>
+		/// <param name="sourceBitmap"></param>
+		/// <returns>IColorQuantizer</returns>
+		public static IColorQuantizer PrepareQuantize(Bitmap sourceBitmap) {
+			IColorQuantizer quantizer = new WuColorQuantizer();
+			quantizer.Prepare(sourceBitmap);
+			using (BitmapBuffer bbbSrc = new BitmapBuffer(sourceBitmap, false)) {
+				bbbSrc.Lock();
+				for (int y = 0; y < bbbSrc.Height; y++) {
+					for (int x = 0; x < bbbSrc.Width; x++) {
+						quantizer.AddColor(bbbSrc.GetColorAt(x, y));
+					}
+				}
+			}
+			return quantizer;
+		}
+
+		public static Bitmap Quantize(Bitmap sourceBitmap, IColorQuantizer quantizer) {
+			Bitmap result = new Bitmap(sourceBitmap.Width, sourceBitmap.Height, PixelFormat.Format8bppIndexed);
+			List<Color> palette = quantizer.GetPalette(255);
+			ColorPalette imagePalette = result.Palette;
+			// copies all color entries
+			for (Int32 index = 0; index < palette.Count; index++) {
+				imagePalette.Entries[index] = palette[index];
+			}
+			result.Palette = imagePalette;
+
+			using (BitmapBuffer bbbDest = new BitmapBuffer(result, false)) {
+				bbbDest.Lock();
+				using (BitmapBuffer bbbSrc = new BitmapBuffer(sourceBitmap, false)) {
+					bbbSrc.Lock();
+					for (int y = 0; y < bbbSrc.Height; y++) {
+						for (int x = 0; x < bbbSrc.Width; x++) {
+							Color originalColor = bbbSrc.GetColorAt(x, y);
+							Int32 paletteIndex = quantizer.GetPaletteIndex(originalColor);
+							bbbDest.SetColorIndexAt(x,y, (byte)paletteIndex);
+						}
+					}
+				}
+			}
+			return result;
+		}
 	}
 }