IOS image processing-crop images

Fix the problem: trim the upper and lower portions of the picture according to a certain length and width ratio, preserving the contents of the middle. Of course, you can also customize the areas you want to trim.

premise: You need to add Framework:CoreGraphics.framework

Code:

-(uiimage*) crop: (uiimage*) theimage{    //Get size of current image    cgsize size = [theimage size];        Create rectangle that represents a cropped image    cgfloat desiredratio = 1.2;        CGFloat croppedwidth = 0.0;    CGFloat croppedheight = 0.0;    CGRect rect;        if (size.height/size.width >= desiredratio) {        croppedwidth = size.width;        Croppedheight = Size.width * desiredratio;        CGFloat difference = (size.height-croppedheight)/2;        Rect = CGRectMake (0.0, difference, croppedwidth, croppedheight);    }    else{        return theimage;    }        Create bitmap image from original image data,    //using rectangle to specify desired crop area    cgimageref imag Eref = Cgimagecreatewithimageinrect ([theimage cgimage], rect);    UIImage *croppedimage = [UIImage imagewithcgimage:imageref];    Cgimagerelease (imageref);    return croppedimage;}

Reference: Online resources, links have been lost