I have following question: How can I scan a complete image to get for

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Asked: June 8, 20262026-06-08T19:41:13+00:00 2026-06-08T19:41:13+00:00

I have following question: How can I scan a complete image to get for

0

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] :
CGBitmapContextGetData: invalid context 0x0 Jul 24 18:31:41
Christians-MacBook-Pro.local Bitmap_Test[2374] :
CGBitmapContextCreateImage: invalid context 0x0 Jul 24 18:31:41
Christians-MacBook-Pro.local Bitmap_Test[2374] :
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