如何将png图像保存到相机胶卷中？

Question

I'd like to save screenshots from my game to camera roll. Right now I'm using UIImageWriteToSavedPhotosAlbum which saves the image in jpg format with way too much ugly jpg artifacts. Is there a way to save an UIImage in png format to camera roll?

Answer 1

First you have to add AssetsLibrary Framework, than like this:

ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];

UIImage *image = ... some image

[library writeImageDataToSavedPhotosAlbum: UIImagePNGRepresentation(image) metadata:nil completionBlock:nil];

Answer 2

The solution pointed out here is now deprecated - this post:

UIImageWriteToSavedPhotosAlbum saves to wrong size and quality

shows how to do this:

UIImage* im = [UIImage imageWithCGImage:myCGRef]; // make image from CGRef
NSData* imdata =  UIImagePNGRepresentation ( im ); // get PNG representation
UIImage* im2 = [UIImage imageWithData:imdata]; // wrap UIImage around PNG representation
UIImageWriteToSavedPhotosAlbum(im2, nil, nil, nil); // save to photo album

Answer 3

Napolit "I'd like to save screenshots from my game to camera roll. Right now I'm using UIImageWriteToSavedPhotosAlbum which saves the image in jpg format with way too much...."

Have just stumbled across your question, most of which I can't answer. however, I do have an EASY & QUICK WAY to grab iPad screens. Simply press the SLEEP/WAKE button and the HOME (round button at bottom of the screen) button at the same time.

Answer 4

这说明了如何将UIImage表示为jpg或png： 将UIImage对象另存为PNG或JPEG文件