裁剪和获取图片代码,ObjC代码库,德仔网

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【ObjC】裁剪和获取图片
作者:宝清 / 发布于2014/11/17/ 592

	- (UIImage *)reSizeImage:(UIImage *)image toSize:(CGSize)reSize
	
	{
	 UIGraphicsBeginImageContext(CGSizeMake(reSize.width, reSize.height));
	 [image drawInRect:CGRectMake(0, 0, reSize.width, reSize.height)];
	 UIImage *reSizeImage = UIGraphicsGetImageFromCurrentImageContext();
	 UIGraphicsEndImageContext();
	
	 return reSizeImage;
	
	}
	
	- (UIImage *)squareImageWithImage:(UIImage *)image scaledToSize:(CGSize)newSize {
	 double ratio;
	 double delta;
	 CGPoint offset;
	
	 //make a new square size, that is the resized imaged width
	 CGSize sz = CGSizeMake(newSize.width, newSize.width);
	
	 //figure out if the picture is landscape or portrait, then
	 //calculate scale factor and offset
	 if (image.size.width > image.size.height) {
	 ratio = newSize.width / image.size.width;
	 delta = (ratio*image.size.width - ratio*image.size.height);
	 offset = CGPointMake(delta/2, 0);
	 } else {
	 ratio = newSize.width / image.size.height;
	 delta = (ratio*image.size.height - ratio*image.size.width);
	 offset = CGPointMake(0, delta/2);
	 }
	
	 //make the final clipping rect based on the calculated values
	 CGRect clipRect = CGRectMake(-offset.x, -offset.y,
	 (ratio * image.size.width) + delta,
	 (ratio * image.size.height) + delta);
	
	
	 //start a new context, with scale factor 0.0 so retina displays get
	 //high quality image
	 if ([[UIScreen mainScreen] respondsToSelector:@selector(scale)]) {
	 UIGraphicsBeginImageContextWithOptions(sz, YES, 0.0);
	 } else {
	 UIGraphicsBeginImageContext(sz);
	 }
	 UIRectClip(clipRect);
	 [image drawInRect:clipRect];
	 UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
	 UIGraphicsEndImageContext();
	
	 return newImage;
	}
	- (CGImageRef)imageFromSampleBuffer:(CMSampleBufferRef)sampleBuffer
	{
	 // Get a CMSampleBuffer's Core Video image buffer for the media data
	 CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
	
	 // Lock the base address of the pixel buffer
	 CVPixelBufferLockBaseAddress(imageBuffer, 0);
	
	 // Get the base address
	 void *baseAddress = CVPixelBufferGetBaseAddressOfPlane(imageBuffer, 0);
	
	 // Get the number of bytes per row for the pixel buffer
	 size_t bytesPerRow = CVPixelBufferGetBytesPerRow(imageBuffer);
	 // Get the pixel buffer width and height
	 size_t width = CVPixelBufferGetWidth(imageBuffer);
	 size_t height = CVPixelBufferGetHeight(imageBuffer);
	
	 // Create a device-dependent RGB color space
	 CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
	
	 // Create a bitmap graphics context with the sample buffer data
	 CGContextRef context = CGBitmapContextCreate(baseAddress, width, height, 8,
	 bytesPerRow, colorSpace, kCGBitmapByteOrder32Little | kCGImageAlphaPremultipliedFirst);
	
	 // Create a Quartz image from the pixel data in the bitmap graphics context
	 CGImageRef quartzImage = CGBitmapContextCreateImage(context);
	
	 // Unlock the pixel buffer
	 CVPixelBufferUnlockBaseAddress(imageBuffer,0);
	
	 // Free up the context and color space
	 CGContextRelease(context);
	 CGColorSpaceRelease(colorSpace);
	
	 // We should return CGImageRef rather than UIImage because QR Scan needs CGImageRef
	 return quartzImage;
	}
试试其它关键字
　裁剪图片　　获取图片　
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