According to aspects of embodiments of the invention, a method of encoding a sequence of frames of image data, each frame including a number of lines of pixels equal to a frame height, and each line having a number of pixels equal to a line length, comprises: encoding as an encoded symbol stream a sequence of pixels of a frame without including an end-of-line code after each line; identifying as a run having a run length, a sequence of pixels having values less than a threshold; and encoding the run using digit encoding. According to other aspects, the digit encoding may further comprise: identifying a set of most frequently used symbols; assigning a symbolic digit to each of the set of most frequently used symbols; assigning a start symbol; and encoding using digit encoding may include: inserting in the encoded symbol stream the start symbol; and inserting in the encoded symbol stream after the start symbol a sequence of symbolic digits identifying the run length of the run. The method may yet further comprise: assigning an end symbol; and inserting the end symbol in the encoded symbol stream after the sequence of symbolic digits. According to yet another variation, the method may further comprise defining the assigned start symbol to include a field indicating how many of the symbolic digits are required to identify the run length of the run.