NSImage <-> CGContextRef

gistfile1.txt

CGContextRef fromImage(NSImage* image)
{
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    NSSize size = [image size];
    CGContextRef contextRef = CGBitmapContextCreate(NULL, size.width, size.height, 8, 0, colorSpace, kCGImageAlphaPremultipliedLast);
    NSGraphicsContext *graphicsContext = [NSGraphicsContext graphicsContextWithCGContext:contextRef flipped:NO];
    
    NSGraphicsContext* currentContext = [NSGraphicsContext currentContext];
    [NSGraphicsContext setCurrentContext:graphicsContext];
    [image drawInRect:NSMakeRect(0, 0, size.width, size.height)];
    [NSGraphicsContext setCurrentContext:currentContext];
    CGColorSpaceRelease(colorSpace);
    
    return contextRef;
}

NSImage* fromContext (CGContextRef context)
{
    CGImageRef imageRef = CGBitmapContextCreateImage(context);
    NSImage* newImage = [[NSImage alloc] initWithCGImage:imageRef
                                                    size:NSMakeSize(
                                                                    CGBitmapContextGetWidth(context),
                                                                    CGBitmapContextGetHeight(context))];
    return newImage;
}