int scaleX = param.getSourceXSubsampling();
int scaleY = param.getSourceYSubsampling();
int xOffset = param.getSubsamplingXOffset();
int yOffset = param.getSubsamplingYOffset();
sourceRegion.translate(xOffset, yOffset);
sourceRegion.width -= xOffset;
sourceRegion.height -= yOffset;
int minX = sourceRegion.x / scaleX;
int minY = sourceRegion.y / scaleY;