IOS UIImage Image upside down
CGAffineTransform myTr = CGAffineTransformMake(1, 0, 0, -1, 0, backImage.size.height);
CGContextConcatCTM(context, myTr);
[backImage drawInRect:CGRectMake(cbx, -cby, backImage.size.width, backImage.size.height)];
myTr = CGAffineTransformMake(1, 0, 0, -1, 0, backImage.size.height);
CGContextConcatCTM(context, myTr);

NSData *imageData = UIImageJPEGRepresentation(backImage, 0);

UIGraphicsBeginImageContextWithOptions(size, isOpaque, 0);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextDrawImage(context, (CGRect){ {0,0}, origSize }, [origImage CGImage]);
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;

NSData *imageData = UIImageJPEGRepresentation(backImage, 0);

1, 0, 0
0, 1, 0
0, 0, 1

CGAffineTransform matrix = CGAffineTransformMake(1, 0, 0, 1, 0, 0);

matrix = CGAffineTransformTranslate(matrix, x, y);

matrix = CGAffineTransformScale(matrix, -1, 1);

matrix = CGAffineTransformScale(matrix, 1, -1);

matrix = CGAffineTransformRotate(matrix, angle);

matrix = CGAffineTransformScale(matrix, imageWidth/viewWidth, imageheight/viewHeight);

CGContextConcatCTM(context, matrix);