1. A computer-implemented method for classifying image data for transmission over a computer network, the method comprising: receiving a plurality of images representative of a target system's graphics usage; testing the plurality of images using a plurality of encoding codecs; encoding the plurality of images using the plurality of encoding codecs; compressing the encoded plurality of images to generate encoded data for transmission over a network stream; testing the compressed encoded plurality of images to determine a set of characteristic responses; and selecting a subset of the characteristic responses for input to an image classifier.