Iphone – UIImageWriteToSavedPhotosAlbum save as PNG with transparency

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I'm using UIImageWriteToSavedPhotosAlbum to save a UIImage to the user's photo album. The problem is that the image doesn't have transparency and is a JPG. I've got the pixel data set correctly to have transparency, but there doesn't seem to be a way to save in a transparency-supported format. Ideas?

EDIT: There is no way to accomplish this, however there are other ways to deliver PNG images to the user. One of which is to save the image in the Documents directory (as detailed below). Once you've done that, you can email it, save it in a database, etc. You just can't get it into the photo album (for now) unless it is a lossy non-transparent JPG.

Best Answer

As pointed out on this SO question there is a simple way to save pngs in your Photo Albums:

UIImage* image = ...;                                     // produce your image
NSData* imageData =  UIImagePNGRepresentation(image);     // get png representation
UIImage* pngImage = [UIImage imageWithData:imageData];    // rewrap
UIImageWriteToSavedPhotosAlbum(pngImage, nil, nil, nil);  // save to photo album

Related Solutions

Iphone – UIImageWriteToSavedPhotosAlbum saves to wrong size and quality

I found a decent workaround, which is to essentially rewrap the UIImage as a PNG, then save the rewrapped version. Code looks something like 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

Iphone – Saving a PNG (or good quality JPG) image to the Photos Library

The best answer of this question can be found here. I'll paste it just in case something happens in the future which would make the link invalid:

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

Thanks to Ben Weiss for this.

Best Answer

Related Solutions

Iphone – UIImageWriteToSavedPhotosAlbum saves to wrong size and quality

Iphone – Saving a PNG (or good quality JPG) image to the Photos Library

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