How do I ensure that photos uploaded via my iOS app aren't blurry?

Question

I'm working on an iPhone art app in which users can export their work to Facebook via photo upload. The images are 320 x 320 and I'm sending over a PNG, created via the UIImagePNGRepresentation function. Uploading works, but once I view the photos on Facebook, they look bad: very blurry. So, I tried sending a bigger file... still blurry. I tried sending a JPEG instead, via UIImageJPEGRepresentation at the highest quality, but still no luck.

I'm doing the upload via a Graph request to "me/photo", with a POST. The request params are "picture" for the image data and "message" for a caption.

I'm using the same code to export to Twitter and Tumblr and the photos look great there, so I'm not sure what I'm doing wrong or if this is just some kind of limitation of Facebook. I haven't been able to find any recommended file type or size in the API docs.

Answer 1

I've had this problem when I designed stuff for Facebook (e.g. a Page's profile pic), saved it as a beautiful PNG, uploaded it, but once on Facebook it would look very bad.

I have found that Facebook, unlike Twitter and Tumblr, compresses all its images using a very low quality JPG setting, so there is nothing you can do here to stop your pics getting blurry other than waiting and hoping that Facebook increases the JPG quality setting, or allows uploading of alternative formats, but I wouldn't hold my breath.