The purpose of this study is to evaluate the performance of two dimensional multi-threaded linear filtering process on the GPU and FPGA platforms. To obtain the implementation on varying platforms, OpenCL API is used. OpenCL provides platform independent programming advantage. The results on three different platforms are compared to each other within this scope. These platforms are CPU, GPU, and FPGA. With changing filter and video frame sizes, varying processing times on these platforms are observed, and platform dependent advantages/disadvantages are studied.