How to crop square area of an image in iOS? - ios

Question

I need to crop and straighten a rotated square area from an UIImage and then store to a new UIImage object. The following picture will make you understand what I want to do. With the locations of point A, B and the width of the square known, how to crop the area out and make it straight? Could you please show me the example code to accomplish this in detail?
Swift or Objective-C is OK. Thanks in advance.

Answer 1

Use This Code For Cropping the Image
// Create the image from a png file
UIImage *image = [UIImage imageNamed:#"myImage.png"];
UIImageView *imageView = [[UIImageView alloc] initWithImage:image];
// Get size of current image
CGSize size = [image size];
// Frame location in view to show original image
[imageView setFrame:CGRectMake(0, 0, size.width, size.height)];
[[self view] addSubview:imageView];
// Create rectangle that represents a cropped image
// from the middle of the existing image
CGRect rect = CGRectMake(size.width / 4, size.height / 4 ,
(size.width / 2), (size.height / 2));
// Create bitmap image from original image data,
// using rectangle to specify desired crop area
CGImageRef imageRef = CGImageCreateWithImageInRect([image CGImage], rect);
UIImage *img = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef);
// Create and show the new image from bitmap data
imageView = [[UIImageView alloc] initWithImage:img];
[imageView setFrame:CGRectMake(0, 200, (size.width / 2), (size.height / 2))];
[[self view] addSubview:imageView];