Image compression technique for low-power, always-on camera systems

A low power system comprising;

• a source of uncompressed video;
• a first compression engine configured to receive the uncompressed video and to produce first compressed video;
• a resynchronization code generator configured to insert resynchronization codes into the first compressed video;
• a low-voltage semiconductor memory coupled to store the first compressed video;
• a decompression unit configured to read the first compressed video from the low-voltage semiconductor memory and to decompress the first compressed video to produce a decompressed video;
• an error checker configured to scan the first compressed video as the first compressed video is read from the low-voltage semiconductor memory;
• a resynchronization code detector configured to scan the first compressed video as the first compressed video is read from the low-voltage semiconductor memory;
• where the decompression unit is configured to stop decompressing video upon the error checker detecting an error in a first frame and to resume decompression upon the resynchronization code detector detecting a resynchronization code.

A method of compressing and storing preview video comprising:

• receiving uncompressed video and performing image compression on a frame of the uncompressed video to generate a compressed frame;
• generating a video stream comprising the compressed reference frame, and a compressed difference frame, and storing the video stream in an extreme low-voltage memory;
• and
• injecting, into the video stream, a plurality of resynchronization codes for the reference frame and a plurality of resynchronization codes for the difference frame, the resynchronization codes comprising a byte sequence unique to resynchronization codes.