Stitch/Composite multiple images vertically and save as one image (iOS, objective-c)

Question

I need help writing an objective-c function that will take in an array of UIImages/PNGs, and return/save one tall image of all the images stitched together in order vertical

Answer 1

I know I'm a bit late here but hopefully this can help someone out. If you're trying to create one large image out of an array you can use this method

- (UIImage *)mergeImagesFromArray: (NSArray *)imageArray {

    if ([imageArray count] == 0) return nil;

    UIImage *exampleImage = [imageArray firstObject];
    CGSize imageSize = exampleImage.size;
    CGSize finalSize = CGSizeMake(imageSize.width, imageSize.height * [imageArray count]);

    UIGraphicsBeginImageContext(finalSize);

    for (UIImage *image in imageArray) {
        [image drawInRect: CGRectMake(0, imageSize.height * [imageArray indexOfObject: image],
                                      imageSize.width, imageSize.height)];
    }

    UIImage *finalImage = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    return finalImage;
}