iphone - Scan complete Image for pixel color
===

I have following question: How can I scan a complete image to get for every pixel it's color.

I use this library https://github.com/unixpickle/ANImageBitmapRep.


I have this code:

    - (void)executeImageScanProcessWithImage:(UIImage *)image{
    

    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 
                                             (unsigned long)NULL), ^(void) {
        
        
        NSString *rowString = @"";
        NSMutableArray *array = [[NSMutableArray alloc] init];
        ANImageBitmapRep *imageBitmap;
        UIColor *color;
        // Loop für die Spalten (y)
        for (int y = 0; y < 320; y += 20) {
            rowString = @""; // rowString zurücksetzen
            
            // Loop für die Reihe (x)
            for (int x = 0; x < image.size.width; x += 20) {
                
                BMPoint pixelPoint = BMPointMake(x, y);
                imageBitmap = [ANImageBitmapRep imageBitmapRepWithImage:image];
                BMPixel pixel = [imageBitmap getPixelAtPoint:pixelPoint];
                color = UIColorFromBMPixel(pixel);
                
                if ([color isEqual:[UIColor redColor]]) {
                    rowString = [rowString stringByAppendingFormat:@"0"];
                }
                else {
                    rowString = [rowString stringByAppendingFormat:@"1"];
                }
                
                // Wenn der letzte "Run" vollzogen ist, wird die rowString in den Array hinzugefügt
                if ([rowString length] == image.size.width / 20) {
                    [array addObject:rowString];
                }
            }
            
            [array addObject:rowString];
        }
        
        NSLog(@"content of array = %@",array);
        
        
    });
    
}

The Problem is that I get this error, when the image gets too big.

> Malloc failed which is too bad.  I was hoping to use this memory. Jul
> 24 18:31:41 Christians-MacBook-Pro.local Bitmap_Test[2374] <Error>:
> CGBitmapContextGetData: invalid context 0x0 Jul 24 18:31:41
> Christians-MacBook-Pro.local Bitmap_Test[2374] <Error>:
> CGBitmapContextCreateImage: invalid context 0x0 Jul 24 18:31:41
> Christians-MacBook-Pro.local Bitmap_Test[2374] <Error>:
> CGBitmapContextGetWidth: invalid context 0x0
> Bitmap_Test(2374,0xb0103000) malloc: *** mmap(size=2265088) failed
> (error code=12)


Do you know another approach to deal with this plan?

Best regards from Germany,
Chris