Overview
MJPEG full name "Motion Joint Photography Group", is a video coding format, Chinese name translation to "Technology," Motion still image (or frame-by-frame) compression technology ". MJPEG is widely used in nonlinear editing fields to accurately go to frame editing and multi-layer image processing, which processes motion of video sequences as a continuous still image, which compresss each frame separately, and can be random in the editing process For each frame, it can be accurate to the frame of the frame, and the compression and decompression of M-JPEG is symmetrical, which can be implemented by the same hardware and software. However, M-JPEG compresses only spatial redundancy within the frame. Do not compress the time redundancy between the frame, so the compression efficiency is not high. The M-JPEG digital compression format is used. When compression is 7: 1, a program equivalent to the betaCam SP quality image can be provided.
Motion JPEG technology is often used for the simulation video signal "translation" of the television camera of the circuit, and stores it on the hard disk. Typical applications such as digital video recorders, etc. MJPEG is unlike MPEG, it is easy to edit with a nonlinear editor. MJPEG's compression algorithm with MPEG, is very powerful, can send high quality pictures, generate full animation video, etc. However, accordingly, MJPEG has a high demand of bandwidth. It is equivalent to T-1, and MJPEG information is a huge substance stored in digital media, requiring a large number of storage space to meet the needs of today's users. So from another perspective, under certain conditions, MJPEG may be one of the lowest efficiency of the encoding / decoder.
Difference
MJPG is the abbreviation of MJPEG, but MJPEG can also represent file format extensions.
The following table is M-JPEG and MPEG4 image compression technology comparison :
| Compression Technology | M-JPEG | MPEG4 | Compression Rate | 20: 1-50: 1 < / TD> | 200: 1-500: 1 | Bandwidth Requirements | 0.5-1.5Mbps | 10kbps-1.0Mbps |
Features
< P> M-JPEG is a dynamic image compression technology developed based on still image compression technology JPEG, which can generate serialized moving images. Its main feature is that it is basically not considering the change between different frames in the video stream, only compresses a frame separately, and its compressed multiple is 20 ~ 80 times, suitable for compression of the static picture, the resolution can be from 352 × 288 to 704 × 576. The conventional JPEG compression technology is directly processed the entire screen, so the entire compressed file transfer completion begins to decompress the imaging screen, and such a way will time consumes ten seconds or even minutes when transmitting a high-resolution screen. The new generation of M-JPEG is a grammatic technology, first transmit low resolution, and then replenish the information of the detail to improve the quality of the picture. M-JPEG compression techniques can get a high-definition video image, and you can flexibly set the video definition and compressed frames per channel. Single screen can be read because of the compressed format, it can be adjusted arbitrarily. M-JPEG is also suitable for video editing because the intra compression mode is used.M-JPEG is that the compression efficiency is low, and the MJPEG algorithm is compressed according to the content of each frame image, rather than according to the difference between the adjacent frame images, thus causing a lot. The redundant information is repeatedly stored, and the storage occupied space is large to 8 ~ 15k bytes per frame, and it is best to achieve 3k bytes per frame, but the video quality will be severely lowered if the high compression ratio is used.