Linux 将 UIImage 保存到文件需要花费大量时间
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saving UIImage to file cost a lot of time
提问by disorderdev
I'm trying to load pictures in iPhone Photos app, then save the selected pictures in to my app's folder, using ALAssetsLibrary, and have two issues: 1. the image file saved to disk is much bigger then original files in Photos app, for example, a picture is 2.8MB, but after saved to my app's folder, it's 6.4MB, following is the code:
我正在尝试在 iPhone 照片应用程序中加载图片，然后使用 ALAssetsLibrary 将所选图片保存到我的应用程序文件夹中，并且有两个问题：1. 保存到磁盘的图像文件比照片应用程序中的原始文件大得多，对于例如，一张图片是2.8MB，但保存到我的应用程序文件夹后，它是6.4MB，以下是代码：
CGImageRef cgImage = [localPhoto thumbnail];
NSString *path = @"/documents/test/1.jpeg";//the path is just an example
BOOL succ;
UIImage *image1 = [UIImage imageWithCGImage:cgImage];
NSData *data1 = UIImageJPEGRepresentation(image1, 1.0);
succ = [data1 writeToFile:path atomically:YES];
- the above code(saving 6.4MB image to file) costs about 1.6seconds, is it normal? is there anyway to make it faster?
- 上面的代码（将 6.4MB 图像保存到文件）大约需要 1.6 秒，这正常吗？有没有办法让它更快？
采纳答案by Anil Sivadas
Try with PNG representation of the image.
尝试使用图像的 PNG 表示。
NSData *data1 = UIImagePNGRepresentation(image1);
or else reduce the image quality or JPG.
否则降低图像质量或 JPG。
NSData *data1 = UIImageJPEGRepresentation(image1, 0.5);
