Digital Formats

Digital Formats

One standardized means of storing and organizing image data in digital photography is the use of image file formats. These files are made up of either pixel or vector (geometric) data, this data is changed to pixels during the display process.

Pixel is the abbreviation for "picture element": "pix" is the common abbreviation for "picture." Pixels are a point in a graphic image -- not really a dot, but a sample of the image.

Image file sizes are expressed in bytes. The bytes increase according to the number of pixels in an image, and the color depth of the pixels also increases the size of the image file.

Image resolution increases with the addition of rows and columns, which also increases the file size.  The image and its storage file increases in size as the color depth is increased. While a 1-byte or an 8-bit pixel can store 256 colors, a 3-byte or 24-bit pixel can store 16 million colors; this is known as truecolor.

Algorithms are used as a method of image compression or decreasing the file in size. Large image files are created by high-resolution cameras, and files can vary from hundreds of kilobytes to many megabytes; this is dependent on the resolution of the camera and the format used to save the images.

A high-resolution digital camera can record 8-megapixel images or more (1 megapixel [MP] is equal to one million pixels). If you were using an 8 MP camera, taking a picture and leaving the files uncompressed, it would require 24,000,000 bytes of memory, because each pixel uses 3 bytes to record true color.

Storing images that size would not be practical, since cameras are required to store many images to make them useful. Image file formats have been developed to address the problem of storing images that large.