CODEWITHSUNDEEP
iosobjective-cimage
Flexsin Flex
Flexsin Flex

Reputation: 123

How to crop center part of large image in iOS?

When a image is cropped from the center then crop image will take the aspect ratio of source image,But According to my requirement, aspect ratio will be change with new crop size.

I want to get exact center part of image with new aspect ratio.For example a large image is of size (320*480) then I want to crop center part of image of size (100,100) and aspect ratio will also be 100*100 ,No outer white or black part is required and image quality will be high.

Cropping function :

- (UIImage *)cropImage:(UIImage*)image andFrame:(CGRect)rect {

    //Note : rec is nothing but the image frame which u want to crop exactly.

    rect = CGRectMake(rect.origin.x*image.scale,
                      rect.origin.y*image.scale,
                      rect.size.width*image.scale,
                      rect.size.height*image.scale);

    CGImageRef imageRef = CGImageCreateWithImageInRect([image CGImage], rect);
    UIImage *result = [UIImage imageWithCGImage:imageRef
                                          scale:image.scale
                                    orientation:image.imageOrientation];
    CGImageRelease(imageRef);
    return result;
}

Please help me.

Upvotes: 4

Views: 8097

Answers (4)

Paresh Navadiya
Paresh Navadiya

Reputation: 38239

Calculate crop rect from image

float imgHeight = 100.0f; //Any according to requirement
float imgWidth = 100.0f; //Any according to requirement
CGRect cropRect = CGRectMake((largeImage.size.width/2)-(imgWidth/2),largeImage.size.height/2)-(imgHeight/2),imgWidth,imgHeight);

Now crop it

CGImageRef imageRef = CGImageCreateWithImageInRect([largeImage CGImage], cropRect);
// or use the UIImage wherever you like
UIImage *croppedImg = [UIImage imageWithCGImage:imageRef]]; 
CGImageRelease(imageRef);

Upvotes: 1

user8098594
user8098594

Reputation:

// Work this code

     -(UIImage *)croppedImage
    {
    UIImage *myImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    [self.bezierPath closePath];
    CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext(), 0.0, 0.0, 0.0, 0.0);
    _b_image = self.bg_imageview.image;
    CGSize imageSize = _b_image.size;
    CGRect imageRect = CGRectMake(0, 0, imageSize.width, imageSize.height);
    UIGraphicsBeginImageContextWithOptions(imageSize, NO, [[UIScreen mainScreen] scale]);
    [self.bezierPath addClip];
    [_b_image drawInRect:imageRect];

    UIImage *croppedImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
return croppedImage;

}

Upvotes: 1

SHEREENA T K
SHEREENA T K

Reputation: 211

var imageView = UIImageView()

// height and width values corresponds to rectangle height and width

imageView  = UIImageView(frame: CGRectMake(0, 0, width, height ))
imageView.image = UIImage(named: "Your Image Name")

// by   setting   content  mode  to  .ScaleAspectFill   image centrally  fill  in   imageView. image   might appear beyond  image frame.

imageView.contentMode = .ScaleAspectFill


// by   setting .clipsToBouds to true,  image set to image frame.

imageView.clipsToBounds = true
view.addSubview(imageView)

Upvotes: 1

Sanjay Goswami
Sanjay Goswami

Reputation: 858

This might run

- (UIImage *)imageByCroppingImage:(UIImage *)image toSize:(CGSize)size
{
    // not equivalent to image.size (which depends on the imageOrientation)!
    double refWidth = CGImageGetWidth(image.CGImage);
    double refHeight = CGImageGetHeight(image.CGImage);

    double x = (refWidth - size.width) / 2.0;
    double y = (refHeight - size.height) / 2.0;

    CGRect cropRect = CGRectMake(x, y, size.height, size.width);
    CGImageRef imageRef = CGImageCreateWithImageInRect([image CGImage], cropRect);

    UIImage *cropped = [UIImage imageWithCGImage:imageRef scale:0.0 orientation:self.imageOrientation];
    CGImageRelease(imageRef);

    return cropped;
}

Upvotes: 13

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