Reputation: 939
Is there any cropping image API for objective C that crops images dynamically in Xcode project? Please provide some tricks or techniques how could I crop camera images in iPhone.
Upvotes: 26
Views: 35415
Reputation: 5248
EDIT - Swift Version
let imageView = UIImageView(image: image)
imageView.contentMode = .scaleAspectFill
imageView.clipsToBounds = true
All these solutions seem quite complicated and many of them actually degrade the quality the image.
You can do much simpler using UIImageView
's out of the box methods.
Objective-C
self.imageView.contentMode = UIViewContentModeScaleAspectFill;
[self.imageView setClipsToBounds:YES];
[self.imageView setImage:img];
This will crop your image based on the dimensions you've set for your UIImageView
(I've called mine imageView
here).
It's that simple and works much better than the other solutions.
Upvotes: 10
Reputation: 95
Xcode 5, iOS 7, and 4-inch screen example: Here is an open source example of a SimpleImageCropEditor (Project Zip and Source Code Example. You can load the Image Crop Editor as a Modal View Controller and reuse. Look at the code and please leave constructive comments concerning if this example code answers the question "Image Cropping API for iOS".
Demonstrates, is example source Objective-C code, use of UIImagePickerController, @protocol, UIActionSheet, UIScrollView, UINavigationController, MFMailComposeViewController, and UIGestureRecognizer.
Upvotes: 1
Reputation: 8320
You can use below simple code to crop an image. You have to pass the image and the CGRect which is the cropping area. Here, I crop image so that I get center part of original image and returned image is square.
// Returns largest possible centered cropped image.
- (UIImage *)centerCropImage:(UIImage *)image
{
// Use smallest side length as crop square length
CGFloat squareLength = MIN(image.size.width, image.size.height);
// Center the crop area
CGRect clippedRect = CGRectMake((image.size.width - squareLength) / 2, (image.size.height - squareLength) / 2, squareLength, squareLength);
// Crop logic
CGImageRef imageRef = CGImageCreateWithImageInRect([image CGImage], clippedRect);
UIImage * croppedImage = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef);
return croppedImage;
}
Upvotes: 18
Reputation: 11
You can use CoreGraphics framework to cropping image dynamically. Here is a example code part of dynamic image crop. I hope this will be helpful for you.
- (void)drawMaskLineSegmentTo:(CGPoint)ptTo withMaskWidth:(CGFloat)maskWidth inContext:(NXMaskDrawContext)context{
if (context == nil)
return;
if (context.count <= 0){
[context addObject:[NSValue valueWithCGPoint:ptTo]];
return;
}
CGPoint ptFrom = [context.lastObject CGPointValue];
UIGraphicsBeginImageContext(self.maskImage.size);
[self.maskImage drawInRect:CGRectMake(0, 0, self.maskImage.size.width, self.maskImage.size.height)];
CGContextRef graphicsContext = UIGraphicsGetCurrentContext();
CGContextSetBlendMode(graphicsContext, kCGBlendModeCopy);
CGContextSetRGBStrokeColor(graphicsContext, 1, 1, 1, 1);
CGContextSetLineWidth(graphicsContext, maskWidth);
CGContextSetLineCap(graphicsContext, kCGLineCapRound);
CGContextMoveToPoint(graphicsContext, ptFrom.x, ptFrom.y);
CGContextAddLineToPoint(graphicsContext, ptTo.x, ptTo.y);
CGContextStrokePath(graphicsContext);
self.maskImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIGraphicsBeginImageContext(self.displayableMaskImage.size);
[self.displayableMaskImage drawInRect:CGRectMake(0, 0, self.displayableMaskImage.size.width, self.displayableMaskImage.size.height)];
graphicsContext = UIGraphicsGetCurrentContext();
CGContextSetBlendMode(graphicsContext, kCGBlendModeCopy);
CGContextSetStrokeColorWithColor(graphicsContext, self.displayableMaskColor.CGColor);
CGContextSetLineWidth(graphicsContext, maskWidth);
CGContextSetLineCap(graphicsContext, kCGLineCapRound);
CGContextMoveToPoint(graphicsContext, ptFrom.x, ptFrom.y);
CGContextAddLineToPoint(graphicsContext, ptTo.x, ptTo.y);
CGContextStrokePath(graphicsContext);
self.displayableMaskImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
[context addObject:[NSValue valueWithCGPoint:ptTo]];
}
Upvotes: 1