cl-jpeg
JPEG encoder implementation using OpenCL
...Look at "Debunking the 100X GPU vs. CPU Myth: An Evaluation of Throughput Computing on CPU and GPU" paper by Victor W Lee, Changkyu Kim, Jatin Chhugani, Michael Deisher, Daehyun Kim, Anthony D. Nguyen, Nadathur Satish, Mikhail Smelyanskiy, Srinivas Chennupaty, Per Hammarlund, Ronak Singhal and Pradeep Dubey.