A method for encoding and decoding frames by generating a key bitstream such that the key bitstream never has to be stored is disclosed. The method consists of a key generation algorithm using a threshold matrix to generate a key that is very similar to original bitmap data. The key generation algorithm searches the bitmap for equivalent image sets that produce the same bitmaps. These equivalent image sets consist of runlength of constant image values and the actual runlength. Additionally, the image values for the runlengths are never explicitly encoded. During compression a preprocess algorithm XORs the MINIMAL number of hints required to find a equivalent image value for the runlength. The postprocess algorithm is capable of distinguishing if a single bit represents an image value adjustment hint or if it represents the end of a runlength. By allowing the image value for each run length to be represented by a series of hints it is possible to avoid specifying the image value with an excessive amount of precession. Excessive precision of the image value simply adds data to the data stream without adding any additional information.