shithub: ifilter

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improved pixelate filter

	use an average of surrounding pixels colors instead of the single
	pixel at (x;y)

--- a/blur.c

+++ b/blur.c

@@ -46,7 +46,7 @@

 pixelate(uchar *data, int w, int h, int depth)

 {

 	uchar *out;

-	int x, y, i, ox, oy, oi;

+	int x, y, i, ox, oy, oi, sr, sg, sb;

 	if(size < 0)

 		sysfatal("pixelate filter needs a size argument");

@@ -55,13 +55,22 @@

 		return nil;

 	for(y = 0; y < h; y += size){

 		for(x = 0; x < w; x += size){

-			i = (x + w * y) * depth;

+			//i = (x + w * y) * depth;

+			sr = sg = sb = 0;

 			for(oy = y; oy < y+size; oy++){

 				for(ox = x; ox < x+size; ox++){

 					oi = (ox + w * oy) * depth;

-					out[oi + 0] = data[i + 0];

-					out[oi + 1] = data[i + 1];

-					out[oi + 2] = data[i + 2];

+					sr += data[oi + 0];

+					sg += data[oi + 1];

+					sb += data[oi + 2];

+				}

+			}

+			for(oy = y; oy < y+size; oy++){

+				for(ox = x; ox < x+size; ox++){

+					oi = (ox + w * oy) * depth;

+					out[oi + 0] = sr / (size*size);

+					out[oi + 1] = sg / (size*size);

+					out[oi + 2] = sb / (size*size);

 				}

 			}

 		}