Hello, i got this message from the debugger: Pixture(1257,0xa0610500) malloc: *** error for object 0x21a8000: pointer being freed was not allocated *** set a breakpoint in malloc_error_break to debug so i did a bit of tracing and got: (gdb) shell malloc_history 1257 0x21a8000 ALLOC 0x2196a00-0x21a89ff [size=73728]: thread_a0610500 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __CFRunLoopDoObservers | CA::Transaction::observer_callback(__CFRunLoopObserver*, unsigned long, void*) | CA::Transaction::commit() | CA::Context::commit_transaction(CA::Transaction*) | CALayerDisplayIfNeeded | -[CALayer _display] | CABackingStoreUpdate | backing_callback(CGContext*, void*) | -[CALayer drawInContext:] | -[UIView(CALayerDelegate) drawLayer:inContext:] | -[AvatarView drawRect:] | -[AvatarView overlayPNG:] | +[UIImageUtility createMaskOf:] | UIGraphicsGetImageFromCurrentImageContext | CGBitmapContextCreateImage | create_bitmap_data_provider | malloc | malloc_zone_malloc and i really can't understand what i am doing wrong. here's the code of the [UIImageUtility createMaskOf:] function: + (UIImage *)createMaskOf:(UIImage *)source { CGRect rect = CGRectMake(0, 0, source.size.width, source.size.height); UIGraphicsBeginImageContext(CGSizeMake(source.size.width, source.size.height)); CGContextRef context = UIGraphicsGetCurrentContext(); CGContextTranslateCTM(context, 0, source.size.height); CGContextScaleCTM(context, 1.0, -1.0); UIImage *original = [self createGrayCopy:source]; CGContextRef context2 = CGBitmapContextCreate(NULL, source.size.width, source.size.height, 8, 4 * source.size.width, CGColorSpaceCreateDeviceRGB(), kCGImageAlphaNoneSkipLast); CGContextDrawImage(context2, CGRectMake(0, 0, source.size.width, source.size.height), original.CGImage); CGImageRef unmasked = CGBitmapContextCreateImage(context2); const float myMaskingColorsFrameColor[6] = { 1,256,1,256,1,256 }; CGImageRef mask = CGImageCreateWithMaskingColors(unmasked, myMaskingColorsFrameColor); CGContextSetRGBFillColor (context, 256,256,256, 1); CGContextFillRect(context, rect); CGContextDrawImage(context, rect, mask); UIImage *whiteMasked = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); return whiteMasked; } the other custom function called before that is the following: - (UIImage *)overlayPNG:(SinglePart *)sp { NSLog([sp description]); // Rect and context setup CGRect rect = CGRectMake(0, 0, sp.image.size.width, sp.image.size.height); NSLog(@"%f x %f", sp.image.size.width, sp.image.size.height); // Create an image of a color filled rectangle UIImage *baseColor = nil; if (sp.hasOwnColor) { baseColor = [UIImageUtility imageWithRect:rect ofColor:sp.color]; } else { SinglePart *facePart = [editingAvatar.face.partList objectAtIndex:0]; baseColor = [UIImageUtility imageWithRect:rect ofColor:facePart.color]; } // Crete the mask of the layer UIImage *mask = [UIImageUtility createMaskOf:sp.image]; mask = [UIImageUtility createGrayCopy:mask]; // Create a new context for merging the overlay and a mask of the layer UIGraphicsBeginImageContext(CGSizeMake(sp.image.size.width, sp.image.size.height)); CGContextRef context2 = UIGraphicsGetCurrentContext(); // Adjust the coordinate system so that the origin // is in the lower left corner of the view and the // y axis points up CGContextTranslateCTM(context2, 0, sp.image.size.height); CGContextScaleCTM(context2, 1.0, -1.0); // Create masked overlay color layer CGImageRef MaskedImage = CGImageCreateWithMask (baseColor.CGImage, mask.CGImage); // Draw the base color layer CGContextDrawImage(context2, rect, MaskedImage); // Get the result of the masking UIImage* overlayMasked = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); UIGraphicsBeginImageContext(CGSizeMake(sp.image.size.width, sp.image.size.height)); CGContextRef context = UIGraphicsGetCurrentContext(); // Adjust the coordinate system so that the origin // is in the lower left corner of the view and the // y axis points up CGContextTranslateCTM(context, 0, sp.image.size.height); CGContextScaleCTM(context, 1.0, -1.0); // Get the result of the blending of the masked overlay and the base image CGContextDrawImage(context, rect, overlayMasked.CGImage); // Set the blend mode for the next drawn image CGContextSetBlendMode(context, kCGBlendModeOverlay); // Component image drawn CGContextDrawImage(context, rect, sp.image.CGImage); UIImage* blendedImage = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); CGImageRelease(MaskedImage); return blendedImage; }