File Formats
There is no specific file format requirements for any particular tout on WBshop. As with web design & development in general, one chooses the most appropriate file format for the type of image. Here is a very broad overview of image file formats.
GIF
- lossy
- animation: yes
- transparency: yes (simple)
- maximum no. of colors: 256
- Best Uses: Imagine an image drawn with horizontal lines, pixel by pixel, starting from the top left. The longer each line goes without changing color, the smaller your file will be. generally better for images with large fields of solid colors, and few colors overall.
JPG
- lossy
- animation: no
- transparency: no
- maximum no. of colors: millions
- Best Uses: JPG compression works by simplifying areas of roughly similar colors. This is why overly compressed JPGs can appear jagged or patchy. Generally better for complex images like photographs.
PNG, 8-bit
- lossy (similar but slightly superior to GIF)
- animation: no
- transparency: yes (alpha channel, far superior to GIF, but unsupported by older versions of Internet Explorer)
- maximum no. of colors: 256
- Best Uses: Similar to GIF.
PNG, 24-bit
- lossless (similar to PICT or TIFF)
- animation: no
- transparency: yes (alpha channel, far superior to GIF, but unsupported by older versions of Internet Explorer)
- maximum no. of colors: millions
- best uses: Almost never. Instead, optimize graphics with one of the above three choices.
PNG, Adobe Fireworks format
- Adobe Fireworks uses PNG as its native source file format. Do not use layered PNG files for the web.
SWF
- At the time of writing, we are not planning on using Adobe Flash on WBshop.com (with the exception of the ezprints builder).
Further Reading
- In Obscuro: Optimizing Images for Web
- About.com: Optimizing Images