Crash when process pixel after crop an image - iphone

Question

After using this function to crop image:
CGImageRef imageRef = CGImageCreateWithImageInRect([self.imageInput CGImage], rect);
UIImage *result = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef);
I bring "result" to use for process with pixel like that:
......
CGContextDrawImage(context, CGRectMake(0, 0, width, height), imageRef);
CGContextRelease(context);
// Now your rawData contains the image data in the RGBA8888 pixel format.
int byteIndex = 0;
for (NSInteger i = 0 ; i < width * height; i++) {
int R = rawData[byteIndex];
int G = rawData[byteIndex + 1];
int B = rawData[byteIndex + 2];
int test = [self getValueof:0.3* R + 0.59* G + 0.11 * B inRange:0 to:255];
rawData[byteIndex] = (char)(test);
rawData[byteIndex + 1] = (char)(test);
rawData[byteIndex + 2] = (char)(test);
byteIndex += 4;
}
ctx = CGBitmapContextCreate(rawData,
CGImageGetWidth( imageRef ),
CGImageGetHeight( imageRef ),
8,
CGImageGetBytesPerRow( imageRef ),
CGImageGetColorSpace( imageRef ),
kCGImageAlphaPremultipliedLast );
imageRef = CGBitmapContextCreateImage (ctx);
UIImage* rawImage = [UIImage imageWithCGImage:imageRef];
CGContextRelease(ctx);
CGImageRelease(imageRef);
free(rawData);
I will have crash? Anyone know about it, please help me.
update crash report: : copy_read_only: vm_copy failed: status 1.

Answer 1

after a long time find solution for this crash. I got an experience:
- When process bitmap on iOS: if we don't notice orientation of image, maybe we got some strange crash.
With my crash above: I have fixed it very simple: change
UIImage *result = [UIImage imageWithCGImage:imageRef];
by
UIImage *result = [UIImage imageWithCGImage:imageRef scale:self.imageInput.scale orientation:self.imageInput.imageOrientation];