EXC_Bad_Access Problems with editable CGImage class

[mraalex]

I wrote an editable CGImage class where you can load images, access the pixels and update them to the image. I am getting EXC_Bad_Access exceptions at different locations in my iphone project, especially when loading a new image and getting a new pixel pointer for an already used instance. Maybe there are some wrong alloc/releases? Can someone please review my code if there are any memory leaks. Thanks, Alex

#import "EditableImage.h"


@implementation EditableImage



- (void) loadImage:(NSString*) name size:(CGSize)size{
        [self clearImage];
        CGImageRef fullImage      = [[UIImage imageNamed:name] CGImage];

    int oldwidth=CGImageGetWidth(fullImage);
    int oldheight=CGImageGetHeight(fullImage);
    int newwidth=size.width;
    int newheight=size.height;
    int width;
    int height;
    fitsize(oldwidth, oldheight, newwidth, newheight, &width, &height);

    image=[self createScaledCGImageFromCGImage:fullImage toWidth:width andHeight:height];
    [self createPixelArray];
}

- (id) init {
    self=[super init];
    image=0;
    return self;
}

- (void) loadImageRef:(CGImageRef) imageRef {
    [self clearImage];
    int width=CGImageGetWidth(imageRef);
    int height=CGImageGetHeight(imageRef);
    image=[self createScaledCGImageFromCGImage:imageRef toWidth:width andHeight:height];

//    image=CGImageCreateCopy(imageRef);
    [self createPixelArray];
}

- (CGImageRef) getImage {
    return image;
}

- (void) clearImage {   

    if (image) {
        CGImageRelease(image);image=0;
    }
}

- (void) createPixelArray {
    data        = (NSData *) CGDataProviderCopyData(CGImageGetDataProvider(image));
}

- (void) updateImage:(char *)pixels {
    // create a new image from the modified pixel data
    CGImageRef imageRef=image;
    size_t width                    = CGImageGetWidth(imageRef);
    size_t height                   = CGImageGetHeight(imageRef);
    size_t bitsPerComponent         = CGImageGetBitsPerComponent(imageRef);
    size_t bitsPerPixel             = CGImageGetBitsPerPixel(imageRef);
    size_t bytesPerRow              = CGImageGetBytesPerRow(imageRef);

    CGColorSpaceRef colorspace      = CGColorSpaceCreateDeviceRGB();
    CGBitmapInfo bitmapInfo         = CGImageGetBitmapInfo(imageRef);
    CGDataProviderRef provider      = CGDataProviderCreateWithData(NULL, pixels, [data length], NULL);

    // the modified image
    [self clearImage];

    image = CGImageCreate (
                                            width,
                                            height,
                                            bitsPerComponent,
                                            bitsPerPixel,
                                            bytesPerRow,
                                            colorspace,
                                            bitmapInfo,
                                            provider,
                                            NULL,
                                            false,
                                            kCGRenderingIntentDefault
                                            );

    //[self createPixelArray];

    // cleanup
    //CGImageRelease(imageRef);
    CGColorSpaceRelease(colorspace);
    CGDataProviderRelease(provider);
    //CGImageRelease(newImageRef); 

}

- (char *) pixelArray {
        return (char *)[data bytes];    
}



- (void)dealloc
{

    if (data) {
        CFRelease(data);data=0;  //causes EXC_Bad_Access when this line is moved into clearImage;
    }
    [self clearImage];
    [super dealloc];
}

- (CGImageRef)createScaledCGImageFromCGImage:(CGImageRef)oimage toWidth:(int)width andHeight:(int)height {
    CGContextRef    context = NULL;
    void *          bitmapData;
    int             bitmapByteCount;
    int             bitmapBytesPerRow;


    // Declare the number of bytes per row. Each pixel in the bitmap in this
    // example is represented by 4 bytes; 8 bits each of red, green, blue, and
    // alpha.
    bitmapBytesPerRow   = (width * 4);
    bitmapByteCount     = (bitmapBytesPerRow * height);

    // Allocate memory for image data. This is the destination in memory
    // where any drawing to the bitmap context will be rendered.
    bitmapData = malloc( bitmapByteCount );
    if (bitmapData == NULL)
    {
        return nil;
    }

    // Create the bitmap context. We want pre-multiplied ARGB, 8-bits
    // per component. Regardless of what the source image format is
    // (CMYK, Grayscale, and so on) it will be converted over to the format
    // specified here by CGBitmapContextCreate.
    CGColorSpaceRef colorspace = CGImageGetColorSpace(oimage);
    //CGColorSpaceRef colorspace=CGColorSpaceCreateDeviceRGB();
    context = CGBitmapContextCreate (bitmapData,width,height,8,bitmapBytesPerRow,
                                     colorspace,kCGImageAlphaPremultipliedLast);
    CFRetain(colorspace);
    CGColorSpaceRelease(colorspace);

    if (context == NULL)
        // error creating context
        return nil;

    CGContextSetInterpolationQuality(context, kCGInterpolationNone);
    // Draw the image to the bitmap context. Once we draw, the memory
    // allocated for the context for rendering will then contain the
    // raw image data in the specified color space.
    CGContextDrawImage(context, CGRectMake(0,0,width, height), oimage);

    CGImageRef imgRef = CGBitmapContextCreateImage(context);
    CGContextRelease(context);
    free(bitmapData);

    return imgRef;
}

@end