Know the Differences Between File Types
When working with image files, the key thing to keep in mind is that there is not just
a single type of image file, there are many! Each type of image has their own benefits and
downfalls which must be looked at so that you may use the correct type for your project. Using the wrong image type could wreck all your work, take up too much disk space or even not show up at all when you display it.
JPEG
JPEG images are the most common image type that you will come across in your travels around the web. JPEG stands for "Joint Photographic Experts Group". What this means is the specific way that the image is compressed has been approved by the photograp
hics expert group to be the best format for an internet-displayed photographic image. There are reasons why you should use JPEG compression and reasons not to, such as:
Benefits
- Small image size
- Viewable from the internet
- Uses millions of colours
- Perfect for most images
Downfalls
- High compression loses quality
- Every time a JPEG is saved, it loses more and more of the picture
The image above is small, needs to be viewed over the internet, and has a lot of detail and color in it, meaning that JPEG compression suits it best.
GIF
GIF images are truly the internet standard for any type of small, simple file. GIF stands for Graphics Interchange Format. The most common use for a GIF is for menu buttons or icons for a webpage. The reason being that GIFs are extremely tiny in file s
ize and have no complex colors, so they load almost instantly on any webpage. Also, any other file which is made up of only use a few basic, flat colors will want to use GIF compression.
Benefits
- Supported by all web browsers
- Very small file size
- Quick to load
- Useful for Transparencies, Animations or Image Maps
Downfalls
- Only basic colors can be used
- Makes complex pictures look horrible
- No detail allowed in images
For more information on the differences between GIFs and JPEGs, see Grantastic Designs page.
BMP - Bitmap
Click the picture for a larger version! (Image of the refresh button from Firefox)
Bitmap files (signified by .BMP extension) are the standard in basic image editing. Bitmaps are exactly as the name says, a map containing many bits of an image. The image displayed above is what a bitmap file would look like very close up. As you can
see, it is just a large array of bits of an image, that when put together, looks like a picture. Since scanners and digital cameras take pictures in this same way (by capturing an group of pixels) most image editing programs will use BMP files for a true
1:1 copy of the file.
Benefits
- High image quality
- Easy to edit and change
- No image loss through process
Downfalls
- Not usually displayable on internet
- Large file size
TIFF
A TIFF file is the industry standard in perfect image editing. Not only is every single color captured to perfection, but it also has zero compression for lossless editing. TIFFs
are the default image type when you are using a professional editing package, such as Adobe's Photoshop. The best place to use a TIFF would be when using the scanners to get a large, detailed image with no loss in quality. The only problem is that TIFF fi
les take up so much room on a disk that they're impossible to put onto a floppy disk, impossible to use on the internet and forget about trying to email one. Not going to happen.
Benefits
- Perfect Image
- You know exactly what the image will look like when you're done
- Never any image loss
Downfalls
- Massive file size prohibits any transferring of the file
- Not viewable on the internet
- Only specialized programs can view it
So now that you know which file types are good for which purposes, image editing and web page creation will be much easier for you. Good luck!