private ArrayList getAvgPixelsList(Bitmap bmp, int stepX, int stepY) {
int xStepsCount = bmp.getWidth() / stepX;
int yStepsCount = bmp.getHeight() / stepY;
ArrayList res = new ArrayList<>(xStepsCount * yStepsCount);
for (int y = 0; y < yStepsCount; y++) {
for (int x = 0; x < xStepsCount; x++) {
res.add(new int[] {x * stepX, y * stepY, getAvgColor(bmp, x, y, stepX, stepY)});
}
}
return res;