We previously learned the way in which an image was coded to be shown on a monitor, however, when we want to store an image in a file, this format is not the most practical…
Indeed, we may want an image which takes up less memory space, or an image which can be increased in size without causing pixelation.
Thus, it is possible to store the image, describing it with an equation, in a file with a data structure, which will need to be decoded by the processor before the information is sent to the graphics card:
There are a great number of file formats. The most commonly used graphic file formats are the following:
| Format | Compression | Maximum dimensions | Maximum number of colors |
|---|---|---|---|
| BMP | None /RLE | 65 536 x 65 536 | 16 777 216 |
| GIF | LZW | 65 536 x 65 536 | 256 |
| IFF | None /RLE | 65 536 x 65 536 | over 16,777,216 |
| JPEG | JPEG | 65 536 x 65 536 | over 16,777,216 |
| PCX | None /RLE | 65 536 x 65 536 | 16 777 216 |
| PNG | RLE | 65 536 x 65 536 | over 16,777,216 |
| TGA | None /RLE | 65 536 x 65 536 | over 16,777,216 |
| TIFF/TIF | Packbits / CCITT G3&4 / RLE / JPEG / LZW / UIT-T | 232-1 | over 16,777,216 |
