As a casual or professional photographer yourself, when you take a digital picture and download it off your camera, what file format do save it in? Do you even know? Do you know what a file format is? This is a major concern and the one that we should all start with. Let me explain the basics over the course of my next two blog entries on the subject.

What's a file format and an extension? Why would I care?

The definition of a photo file format is as follows: A file format is the layout of digital photographic information in terms of how the data within the file is organized to construct the visual image that you see on your screen. A computer program that uses the data in a file must be able to recognize and possibly access data within the photo file via an application designed to read image format. For example, a current popular photo editing program like Adobe Photoshop is able to process and display a file in a multitude of formats so that it appears as an image on the web, or maybe high-res printed material. Both uses require a separate file format. The web uses .JPEG as a standard full color image format and for print .EPS or .TIFF is a standard. If you tried to open a .TIFF file in a web browser you would get extremely mixed results if any. Similarly, if you tried to place a .JPEG file into a printed document it would appear as slightly blurry and low resolution — if the program accepted it at all.

A particular file format is often indicated as part of a file’s name by a file name extension added to the end of the file name. The extension usually consisting of 3-4 characters and is separated from the file name by a period. (FILENAME.EXTN) A program that uses or recognizes a particular file format may or may not care whether the file has the appropriate extension name since it can actually examine the information in the file to see whether the photo format is one it recognizes. As a “best practice” though it is always a good habit to label your files with extensions instead of just a file name. This will help you quickly identify the file format and ensure that future programs will be able to identify that file as well. Popular photo extensions include .jpg, .gif, .tif, .eps, .png, .bmp, etc. and they all have specific uses. Other possible formats include .psd, .pdf, .pcx, Kodak PCD, .pict, .pixar, Scitex CT, Targa plus formats only readable by the application that created the image.

Article Author: Christopher Auman

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