Image Format

  • Image file formats are means of organizing and storing digital images.
  • Image file are composed of digital data in one of these formats that can be rasterized for use on computer display or printer.
  • An image file format store data in uncomposed, composed, or vector formats.
Types of Image Formats:
  1. Raster formats.
  2. Vector formats
  3. Metafile formats
  4. Stereo formats

1. Raster Formats:

  • The major formats are JPEG, Exif, TIFF, GIF, BMP, PNG.
JPEG (Joint Photographic Experts Group) : 
  • It is a lossy compression method.
  • JPEG-compressed images are usually stored in the JFIF (JPEG File Interchange Format) file format.
  • Every digital camera can save images in the JPEG/JFIF format, which supports eight-bit grayscale images and 24-bit color images.
  • It is a file standard similar to the JFIF format with TIFF extension.
  • It is incorporated in the JPEG-writing software used in most cameras.
  • Its purpose is to record and to standardize the exchange of images with image metadata between digital cameras and editing and viewing software.
  • The actual Exif metadata as such may be carried within different host formats.


TIFF (Tagged Image File Format) :
  • It is very flexible format, it supports several types of compression like JPEG, LZW, ZIP.
  • High quality image format, all colors and data information are stored.
  • It can be saved with layers.
  • It makes very large file size, long transfer time, huge disk space consumption, and slow loading time.


BMP (Bitmap) :
  • Works well with most Windows programs and OS, we can use it as a Windows wallpapers.
  • These files are large and uncompressed, but the images are rich in color, high quality.
  • But the image size is large so it is not web friendly.


GIF (Graphic Interchange Format) :
  • It is limited to the 8-bit palette with 256 colors only.
  • It is still popular image format because image size relatively small compare to other compression types.
  • It has not update since, and sometime, the file size larger than PNG.
   


PNG (Portable Network Graphics) :
  • It is an image format specially designed for web.
  • It is a superior version of GIF.
  • It saved with 256 colors maximum but it saves the color information more efficiently.
  • It is not designed for print graphics.
  • But all web browser not support the PNG.


Some examples of Raster Format:



2. Vector Formats:
  • It contains the CGM, Gerber format, SVG.
  • It is more quality than raster format.


CGM (Computer Graphics Metafile) :
  • The file extension, CGM means, 'Computer Graphics Metafile'.
  • It supports lots of systems.
  • It needs filters.


Gerber Format:
  • It is 2D bi-level image description format.
  • It is a de facto format used by the PCB software.
  • It is also widely used in other industries requiring high precision 2D bi-level images.


SVG (Scalable Vector Graphics) :
  • It is a open standard format created and developed by World Wide Web Consortium to address the need for a versatile, scriptable and all purpose vector format for the web and otherwise.
  • It does not have compression scheme of its own due to the textual nature of XML.
  • SVG graphics can be compressed using program such as gzip, because of scripting potential.
  • It is key component in Web application.


3. Metafile Format:
  • It contains the both raster and vector format, and interactive feature of PDF. 
  • It contains EPS, PDF, PostScript, PICT, SWF, XAML.
4. Stereo Format: 
  • MPO (Multi Picture Object) :  This format consists of multiple JPEG images(Camera & Imaging products association).
  • PNS:  It is a PNG stereo format, it consists of side by side images based on PNG.
  • JPS:  It is JPEG stereo format consists of side by side format based on JPEG.  
My notes images: