An Overview of the Different Image File Formats

You may have seen some of these acronyms after the file names of your images and wondered what exactly they mean. These are called file formats and are the different ways your photos will be processed and converted by the camera when being stored as a digital file. Each one has its own characteristics that affect how your image will look when you view it.

There are two kinds of conversions: lossy and lossless. File formats that discard data captured by the camera are called ‘lossy’. They cut down on certain photographic details that our eyes might not perceive. Lossy conversions will also diminish the size of the original image data file. On the other hand, lossless conversions retain all of the data that your camera captures.

JPEG (Joint Photographic Experts Group) – this is probably the most commonly used image format since all photo editing programs and digital cameras can manage it. It is a lossy conversion, which means data is stripped and compressed. This allows more space in the camera’s memory card for more image files to be stored. Since data is removed, this can affect image quality. If there is too much compression, the photos can appear pixelated.

RAW – this is not an acronym. Meaning ‘unprocessed’, RAW is also often referred to as ‘digital negative’. This is a lossless conversion where all the image data remains intact and can be retrieved with a RAW converter program. This is a great advantage for serious photographers who want to have full control over what image data to keep and what to remove during post processing. Not all digital cameras are capable of RAW and not all photo editing programs can handle them, either. Many photographers whose cameras do have this function might not make use of it since it takes longer to process due to the huge file data.

TIFF (Tagged Image File Format) - also a lossless format, these have big files and can therefore be used to produce high quality pictures. TIFF files are very flexible which is what makes them also complex. They can be compressed like JPEGs but not to a great extent.

GIF (Graphics Interchange Format) – created in the 1980s, it is a lossy conversion format that compresses 16 million colors to only 256. This is the preferred format compared to JPEG for images that use only a few colors, those with large sections of the same color, and pure black and white images such as line drawings.

PNG (Portable Network Graphics) – another lossless conversion, this was created to improve upon the older GIF format. There is no worry that this format might not be recognized since it is accepted by all current web browsers. It can compress more efficiently than GIF although there is not that big a difference.