Major memory problem/crash with UIImage

Question

Hi,
Our app needs to render the screen to an UIImage and everytime we do that, the memory utilization of app goes up by about 0.3M [as shown by XCode execution panel, but the Instruments panel shows 3M - see below] eventually causing memory warning and crashing.
The code used is simple - from the example code of Apple:
    UIGraphicsBeginImageContext(self.view.bounds.size);
    [self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
I've tried many ways to reclaim this memory, but there is unbounded growth.
We've checked it many times and there are no leaks, etc.
It is not allocated using imageNamed so I understand it is not cached - regardless we even called  [super didReceiveMemoryWarning] to try to flush the cache, but no luck.
In XCode instruments, the allocations show huge nearly 3MB  growth  as below:
Event Type
∆ RefCt
RefCt
Timestamp
Responsible Library
Responsible Caller
0
VM Alloc
02:08.145.871
CoreGraphics
CGDataProviderCreateWithCopyOfData
The LiveBytes increases by 3MB everytime the UIImage is allocated and RELEASED by the app.
Graph
Category
Live Bytes
# Living
# Transient
Overall Bytes
# Overall
Bytes Allocated (Net / Overall)
1
All Heap & Anonymous VM
12.16 MB
11263
3422178
597.30 MB
3433441
<XRRatioObject: 0x7fbca501d950>  %0.02, %0.98
WHY is this NOT RELEASED by iOS? Can someone help - our app is crashing and rendering the screen to an image is a core part of the functionality.
Thanks,
RFS

Answer 1

I am having the same problem, it is leaking all the memory. It works fine on iOS 6, but it is causing me Memory Warnings on iOS 7.
This is my code
CGImageRef imageRef = image.CGImage;
    // System only supports RGB, set explicitly and prevent context error
    // if the downloaded image is not the supported format
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef context = CGBitmapContextCreate(NULL,
            CGImageGetWidth(imageRef),
            CGImageGetHeight(imageRef),
            8,
            // width * 4 will be enough because are in ARGB format, don't read from the image
            CGImageGetWidth(imageRef) * 4,
            colorSpace,
            // kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Little
            // makes system don't need to do extra conversion when displayed.
            kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Little);
    CGColorSpaceRelease(colorSpace);
    if ( ! context) {
        return nil;
    CGRect rect = (CGRect){CGPointZero, CGImageGetWidth(imageRef), CGImageGetHeight(imageRef)};
    CGContextDrawImage(context, rect, imageRef);
    CGImageRef decompressedImageRef = CGBitmapContextCreateImage(context);
    CGContextRelease(context);
    UIImage *decompressedImage = [[UIImage alloc] initWithCGImage:decompressedImageRef];
    CGImageRelease(decompressedImageRef);
    return [decompressedImage autorelease];