1. A computer-implemented method, comprising: identifying, at a host machine, a current image of a stream of images generated by a virtual machine (VM) executing on the host machine, the stream of images including images previously transmitted to a client associated with the VM via a network; for each segment of pixels in the current image, searching a dictionary using the segment of pixels, the dictionary storing data for the stream of images; and if the dictionary includes data corresponding to the segment of pixels in the current image, determining metadata for the segment of pixels in the current image using the corresponding data from the dictionary, and transmitting the metadata to the client without transmitting the segment of pixels from the current image.