I'm trying to pixelate an animation.. I have a .png image where I cut in frames. I have a scrollbar who gives a number, which is the new size of every pixel. (rasterSize) I already did it for an image and it's working. http://bht-homework.com/RMA/PIX_PRES1/
But for animation it looks like doesn't calculate the first pixels. http://bht-homework.com/RMA/PIX_PRES2/
var imgData=context.getImageData(0,0,img.width,img.height);// width is 190,height 240
for (var x = 0; x < spriteSizeWidth; x++) {
for (var y = 0; y < spriteSizeHeight; y++) {
var rasterX = ((x / rasterSize) | 0) * rasterSize;
var rasterY = ((y / rasterSize) | 0) * rasterSize;
var rasterValIndex = (rasterX + rasterY * imgData.width) * 4;
r=imgData.data[rasterValIndex];
g=imgData.data[rasterValIndex + 1];
b=imgData.data[rasterValIndex + 2];
a=imgData.data[rasterValIndex + 3];
context.fillStyle="rgba(" +r+","+g+","+b+","+a+")";
context.fillRect(x,y,rasterSize,rasterSize);
}
}
Does someone has an idea how to fix it? Thanks!
Though it might look as it would skip the first few pixels of your image, it actually just draws the blocks at the wrong position. It's offset by rasterSize.
You need to shift back the pixels to the correct position.
So simply replace
context.fillRect(x, y, rasterSize, rasterSize);
by
context.fillRect(x - rasterSize, y - rasterSize, rasterSize, rasterSize);