Photoshop Tutorials
Image File Types
There a a number of different image file formats. Each has different properties is are suitable for most different uses such as printing or web sites.
Two of the most common image file formats are JPG &.Tiff
JPG Files
JPG files are commonly used for web sites, emails and are used for saving images on many digital cameras.
JPG files are compressed so that the file size is smaller. However JPG compression is what is know as "lossy" compression - and it damages the image quality.
Each time a JPG file is re-saved, it causes more damage to the image and this can result in a blotchy pattern on what would otherwise be smooth areas of colour, or jagged edges along lines of contrast such as text or sharp edges.
Tiff files
Tiff files are used for saving high quality photographs and for saving images for printing.
Tiff files can be saved as either uncompressed or compresed.
The type of compression used in Tiff files is known as "lossless", and it doesn't cause any damage to the image quality (unlike with JPG files).
Tiff files are quite large file sizes, compared to JPG files
Web file formats
JPG
PNG
GIF
SVG
Print file formats
Tiff
JPG
Photoshop - editable files
PSD
Acrobat for digital documents or printing