The Go runtime (the version that is in google appengine) package image/jpeg returns "unsupported JPEG feature: progressive mode" when trying to Decode a JPEG that uses progressive format. Is this an error on my part? Or is this type of JPEG not yet decodable in Go?
It will be included in the upcoming Go 1.1 release.
Revision: 51f26e36ba98: image/jpeg: decode progressive JPEGs.