裁剪后,图像变得紧张和模糊 [英] Image is getting stretched and blur after crop
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问题描述
我是拥有和UIImageView,UIImageView上还有另一个画布视图。我想根据画布视图的框架剪切UIImageView的图像。但是裁剪完成后,图像会变得紧张并且在裁剪后变得模糊。以下是我的代码。
I am having and UIImageView and there is another canvas view over the UIImageView. I want to cut the UIImageView's image according to the canvas view's frame. But after crop the image is getting stretched and blur after crop. Below are my codes.
[UIImage *images = [self captureScreenInRect1:canvas.frame];
self.imgViewCurrent.contentMode = UIViewContentModeScaleToFill;
self.imgViewCurrent.image = images;
- (UIImage *)captureScreenInRect1:(CGRect)captureFrame {
CALayer *layer;
layer = self.view.layer;enter image description here
UIGraphicsBeginImageContextWithOptions(self.view.bounds.size, NO, 1.0);
CGContextClipToRect (UIGraphicsGetCurrentContext(),captureFrame);
[layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *screenImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
CGImageRef imageRef = CGImageCreateWithImageInRect([screenImage CGImage], captureFrame);
UIImage *img = [UIImage imageWithCGImage:imageRef scale:0.0 orientation:UIImageOrientationUp];
CGImageRelease(imageRef);
return img;
}
推荐答案
裁剪后您可以使用自定义尺寸调整图像大小。它可能会帮助你。
After cropping your image, you can resize your image with Custom Size. It may help you.
-(UIImage*) resizedImage:(UIImage *)inImage: (CGRect) thumbRect
{
CGImageRef imageRef = [inImage CGImage];
CGImageAlphaInfo alphaInfo = CGImageGetAlphaInfo(imageRef);
// There's a wierdness with kCGImageAlphaNone and CGBitmapContextCreate
// see Supported Pixel Formats in the Quartz 2D Programming Guide
// Creating a Bitmap Graphics Context section
// only RGB 8 bit images with alpha of kCGImageAlphaNoneSkipFirst, kCGImageAlphaNoneSkipLast, kCGImageAlphaPremultipliedFirst,
// and kCGImageAlphaPremultipliedLast, with a few other oddball image kinds are supported
// The images on input here are likely to be png or jpeg files
if (alphaInfo == kCGImageAlphaNone)
alphaInfo = kCGImageAlphaNoneSkipLast;
// Build a bitmap context that's the size of the thumbRect
CGContextRef bitmap = CGBitmapContextCreate(
NULL,
thumbRect.size.width, // width
thumbRect.size.height, // height
CGImageGetBitsPerComponent(imageRef), // really needs to always be 8
4 * thumbRect.size.width, // rowbytes
CGImageGetColorSpace(imageRef),
alphaInfo
);
// Draw into the context, this scales the image
CGContextDrawImage(bitmap, thumbRect, imageRef);
// Get an image from the context and a UIImage
CGImageRef ref = CGBitmapContextCreateImage(bitmap);
UIImage* result = [UIImage imageWithCGImage:ref];
CGContextRelease(bitmap); // ok if NULL
CGImageRelease(ref);
return result;
}
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