使用CoreImage过滤图像会导致图像旋转 [英] Using CoreImage to filter an image results in image rotation

问题描述

感谢您阅读。

我正在尝试在iOS 5中使用CoreImage来改变图像的外观。问题是现有图像在此过程中似乎丢失了方向信息并最终旋转了90度。

I'm trying to use CoreImage in iOS 5 to alter the appearance of an image. The problem is that the existing image appears to lose its orientation information during the process and ends up rotated by 90 degrees.

以下是代码：

CIContext *context = [CIContext contextWithOptions:nil];
CIImage *img = [CIImage imageWithCGImage:imageView.image.CGImage];
CIFilter *adjustFilter = [CIFilter filterWithName:@"CIHighlightShadowAdjust"];

[adjustFilter setDefaults];
[adjustFilter setValue:img forKey:kCIInputImageKey];
[adjustFilter setValue:[NSNumber numberWithFloat:0.3] forKey:@"inputShadowAmount"];
CIImage *adjustedImage = [adjustFilter valueForKey:kCIOutputImageKey];
UIImage *newPtImage = [UIImage imageWithCGImage:[context adjustedImage fromRect:adjustedImage.extent]];

imageView.image = newPtImage;

原始图像通常来自相机拍摄的图像，但并非总是如此。

The original image generally comes from one taken by the camera, but not always.

希望有人可以提供帮助。

Hope someone can help.

Rob。

推荐答案

看一下这个答案 https://stackoverflow.com/q/538064/871102

您可以解决将图像传递给上一个答案方法的问题。所以代替：

You can solve your problem passing the image to the method of the previous answer. So instead of:

CIImage *img = [CIImage imageWithCGImage:imageView.image.CGImage];

写：

UIImage *fixedImage = [self scaleAndRotateImage:imageView.image];
CIImage *img = [CIImage imageWithCGImage:fixedImage.CGImage];

更新：

这里有一个更优雅的答案，没有图像缩放： iOS UIImagePickerController结果图片上传后的方向。

There is a more elegant answer without image scaling here: iOS UIImagePickerController result image orientation after upload.

这篇关于使用CoreImage过滤图像会导致图像旋转的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！