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I use Skype and I'm trying to upload a profile image from an iOS device that has a transparent background. Every time I save the image to any iOS device, the transparent background turns black :-/ I have the exact image I want on OSX Skype but it doesn't sync the profile picture across iOS devices. I've re downloaded the app but so far nothing's worked. Is anyone else experiencing this issue or knows how to solve it?

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Simply put, iOS uses the JPEG format when saving images to the Camera Roll, and JPEG does not have an alpha channel for transparency. When converting a PNG image to JPEG, all transparency data is lost. What is happening is the color 0x00000000 (RGBA - four octets) is being changed to 0x000000 (RGB - three octets).

  • I guess I should clarify. The conversion takes place when saving an image using iTunes or iPhoto. There are other times that iOS converts it to JPEG, too. Depending on the image type, I believe Mobile Safari also converts to JPEG (GIF images being a known exception). – Andrew Larsson Nov 15 '13 at 19:07
  • Saving small images as PNG using Apple photo API will result in a JPEG being saved. After a certain size, around 1024x1024 they start properly being saved as PNG with transparent background. The app you are using has to explicitly save as PNG to get the transparent background, and there is no known work-around to fix smaller PNG being saved as JPG. I am very much aware of the issue with my app, You Doodle. – jjxtra Sep 20 at 15:40

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