A progressive differential motion JPEG codec is disclosed. The compression encoder of the progressive differential motion JPEG codec comprises a video capture unit, a video capture buffer, a detection unit, a compression unit, and a quality level buffer. The video capture unit is used for receiving an image data and dividing a component of the image data into a plurality of image data blocks. The video capture buffer stores the image data block. The detection unit is electrically coupled to the video capture unit and the video capture buffer for detecting whether a content of the image data block input from the video capture unit is different from a content of the image data block retrieved from the video capture buffer. The compression unit is electrically coupled to the detection unit for compressing the image data block retrieved from the video capture buffer with a predetermined level compression scheme depending on the difference between the content of the image data block input from the video capture unit and the content of the image data block retrieved from the video capture buffer. The quality level buffer assigns and stores an index value indicative of level compression scheme in the quality level buffer when the compression unit compresses the image data block retrieved from the video capture buffer.