CGRect rect=CGRectMake(_xstep*j, _ystep*i, _xstep, _ystep);
CGImageRef imageRef=CGImageCreateWithImageInRect([image CGImage],rect);
UIImage* elementImage=[UIImage imageWithCGImage:imageRef];
UIImageView*_imageView=[[UIImageView alloc] initWithImage:elementImage];
_imageView.frame=rect;
UIGraphicsBeginImageContext(CGSizeMake(self.targetSize.width*scale, self.targetSize.height*scale));
[self.sourceImage drawInRect:CGRectMake(-startX*scale, -startY*scale, imageViewSize.width*scale, imageViewSize.height*scale)];
UIImage* image = UIGraphicsGetImageFromCurrentImageContext();