- Image CODEC'S is a method of compression/decompression of image files or image data.
- Their are number of CODEC'S available for images.Those are differentiated according to the compression technology / algorithm,platform supported ,etc.
- The various image CODEC'S are :
1.BMP
2.GIF
3.JPEG
4.JPEG2000
5.MJPEG
6.JIFF
7.PNG
8.WBMP
BMP CODEC'S :
Advantages :
- High quality in photos.
- Easy to convert this type of codecs to dot-format devices.
Disadvantages :
- BMP CODEC'S are supports limited color in images (supports only RGB colored images).
- These CODEC's does not support effective image compression.
- Compressing this image codecs by deciminating(removing the pixels) can change the image to the unacceptable manner.
GIF CODEC'S :
Advantages :
- This codecs allows you to create transparent, interlaced, and animated graphics for the Web.
- This codecs Compresses by scanning horizontally across a row of pixels.
- The only graphic file format (codec) that is universally supported by all graphical browsers, regardless of version.
- Most popular and versatile format for distributing color image on the Web.
Disadvantages :
- This codec is not good for photographic images due to its limited number of colors generally 256 colors.
JPEG CODEC'S :
Advantages :
- JPEG codec has low complexity. Picture quality is generally good enough.
- This is also memory efficient. i.e. good compression allows to reduce the file size.
- It works very well for “slide-show” movies that have a very low frame rate.
- Also it has reasonable coding efficiency
Disadvantages :
- Single Resolution & Single Quality.
- No target bit rate.
- Blocking artifacts at low bit rate.
- No lossless capability.
- Poor error resilience.
- No tiling & No regions of interest.
MJPEG CODEC'S :
Advantages :
- MJPEG codecs are often used as storage formats for large files that need to be archived with good quality. It is a lossy codec, but at 100% quality, the image degradation is minimal.
- At WWW data rates (5-20K), JPEG may produce better results than Cinepak.
Disadvantages :
- All the JPEG codecs require significant amounts of CPU power and are not well suited to video playback at CD-ROM or higher data rates, except when assisted by a hardware capture card.
- Large image and/or high frame rate movies usually don’t play smoothly.
TIFF CODEC'S :
Advantages :
- Compared to a JPEG, an uncompressed TIFF codec retains the best quality of a photographic image, making it ideal for digital masters (preservation) and print documents.
- Low or high-resolution images codec of photographic quality (images containing many colors that blend and fade). Encoding scheme is Lossless; files can be compressed or uncompressed.
Disadvantages :
- Codecs produce large file size.
PNG CODEC'S :
Advantages :
- A better compression than GIF codec, which only scans rows. The compression is ‘lossless’, you do not lose color information as you compress the file smaller. Typically compresses images 5-25% better than GIF.
- It is a best one for creating complex live transparency, high-color graphics, and better compressed low-color graphics.
- Designed to be network-friendly, so it is recognized and supported on all platforms.
Disadvantages :
- It doesn’t support animation.
- It does not use predictive frames.
- It has lower quality than PICT or TIFF.
