File Formats

File format refers to the way that information is encoded for storage in a computer file. There are many different file formats some of which are designed for particular types of data. When working with images, knowing which image type to use ensures that you make the most out of your photographs. The main file formats that we will use are: RAW, TIFF, JPEG, GIF, PNG.

RAW

A RAW file contains the direct image data from the camera and is the most common file format for uncompressed images taken by digital cameras. Because they are uncompressed they are large in size. The RAW format stores the fullest details of the image taken with lossless* quality so that they can be edited at a later date.

TIFF

Stands for "Tagged Image File Format", it is a variable resolution bitmapped image format. This is a standard file format used for printing/publishing. Because there are many possible variations, TIFF files are also large in size.

JPEG

Stands for "Joint Photographic Experts Group". This is the standard format used by digital cameras to store photographs and also displaying photographic images on the Internet. JPEG uses lossy* compression so are significantly smaller in size than TIFF & RAW files.

GIF

Stands for "Graphics Interchange Format". A GIF is a lossless* format for image files that support still and animated images. GIF files are small in size because they use a limited number of colours.

PNG

Stands for "Portable Graphics Format". PNG is also a lossless* format used to store web graphics and images with transparent backgrounds. PNG files maintain their original quality when compressed but because they support millions of colours they are typically larger in size than JPEGs and GIFs

What differentiates image types is whether they are compressed.

Compressed files are smaller than uncompressed files and can be either "Lossy" or "Lossless".

  • Lossy-reduces the file size by selectively discarding image data. Meaning that the compressed file is no longer identical to the original image.
  • Lossless-reduces the file size, but ensures that all the image information is preserved.