Image File Formats

Image File Formats

1. JPEG

   • Uses 24 bit for colours
   • Maximum of 16.7 million colours
   • Used for images with continuous colour (e.g. photos)
   • Uses compression
   • Transparency
   • Advantages
     • Widely supported on the internet
     • Can be opened and viewed in almost all viewing applications
     • Compatible with all printers
   • Disadvantages
     • When compressed looses quality
     • Cannot have transparent backgrounds
     • Doesn't support animation

2. GIF

   • Uses 8 bit for colour
   • Maximum of 256 colours
   • Uses compression
   • Used for simple graphics
   • Uses transparency
   • Advantages
     • Most software supports it
     • Can use transparency
     • Doesn't loose quality when compressed
   • Disadvantages
     • limited amount of colours (265)
     • Can't correct colour backgrounds on gifs
     • Takes up a lot of memory space

3. PNG

   • Creates compressed images without loosing quality
   • Uses 16 million Colours
   • Resulting file sizes are larger than GIF or JPEG
   • Advantages
     • when compressed do not loose quality
     • supports 24-bit colour
   • Disadvantages
     • not as small of a file size as JPG images
     • comes with a number of extension formats

4. TIFF

   • Bitmapped image format
   • Suited to scanned images, images wit continuous colours and photographs
   • Can be easily modified
   • Use any number of colours
   • Advantages
     • good format to print in
     • can be used on a variety of platforms e.g. windows and mac OS
     • Supports different levels of depths from 1-32 bit
   • Disadvantages
     • Has large file sizes
     • no compression is used
     • cameras cannot save many images in TIFF file format

5. PSD

   • Photoshop Documents
   • Produce very high quality images
   • No Compression
   • Large file sizes
   • Have slow upload and download speeds
   • Advantages
     • allows layers
     • can save significant amounts of information
   • Disadvantages
     • very large file sizes because of no compression
     • only available in Photoshop
     • difficult to download/upload or email

6. BMP

   • Map of pixels
   • Supports millions of colours
   • File sizes are very large
   • Slow download speed
   • MS Paint files are saved as BMP
   • Photographs can also be saved as BMP
   • Advantages
     • easy to create
     • can be re-coloured
     • Well known
   • Diadvantages
     • If re-sized can loose quality
     • requireed high-resolutions
     • Can only be used on the platform that it is created on e.g. on microsoft

7. EPS

   • Standard format for importing and exporting PostScript files.
   • Can contain text, graphics and images
   • Contain small preview images
   • Photoshop can save bitmap images in this file format
   • Advantages
     • ideal for importing into graphics software
     • can be used on a variety of platforms e.g. transferred fro Mac OS to PC
   • Disadvantages
     • Large file sizes