Unable to set frame of masked Image - Objective C

Question

I have two images one is background image and one is masked image.

I am cropping background image based on masked image.

Background Image With Mask Image:

Result Image:

Following method is being used for cropping:

- (UIImage*) maskImage:(UIImage *)image withMask:(UIImage *)maskImage {
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();

    CGImageRef maskImageRef = [maskImage CGImage];

    // create a bitmap graphics context the size of the image
    CGContextRef mainViewContentContext = CGBitmapContextCreate (NULL, maskImage.size.width, maskImage.size.height, 8, 0, colorSpace, kCGImageAlphaPremultipliedLast);
    CGColorSpaceRelease(colorSpace);

    if (mainViewContentContext==NULL)
        return NULL;

    CGFloat ratio = 0;

    ratio = maskImage.size.width/ image.size.width;

    if(ratio * image.size.height < maskImage.size.height) {
        ratio = maskImage.size.height/ image.size.height;
    }

    CGRect rect1  = {{0, 0}, {maskImage.size.width, maskImage.size.height}};
    CGRect rect2  = {{-((image.size.width*ratio)-maskImage.size.width)/2 , -((image.size.height*ratio)-maskImage.size.height)/2}, {image.size.width*ratio, image.size.height*ratio}};


    CGContextClipToMask(mainViewContentContext, rect1, maskImageRef);
    CGContextDrawImage(mainViewContentContext, rect2, image.CGImage);


    // Create CGImageRef of the main view bitmap content, and then
    // release that bitmap context
    CGImageRef newImage = CGBitmapContextCreateImage(mainViewContentContext);
    CGContextRelease(mainViewContentContext);

    UIImage *theImage = [UIImage imageWithCGImage:newImage];

    CGImageRelease(newImage);

    // return the image
    return theImage;
}

Issue

Problem I am facing is that the mask Image is not taking the actual frame as shown above in background with mask image.

I tried playing with ratio and rect1 and rect2 but couldn't acheive the desired result.

Expected Image: Image with exact frame of masked Image.

It would be great if someone show me the light.