digital photos explained
The Fundamentals of Digital Imaging
An image, of course, is any visual representation. Still images, such as photographs and drawings, capture a single visual moment in time; while moving images and video, such as television and movies, can capture entire periods of time.
A digital image is simply an image that can be represented in the numerical or digital language of a computer. A digital image is made up of millions of tiny dots called pixels. If you look closely at a computer monitor, you can probably see these little dots at the edges of curved images, like letters, for example. These pixels can be displayed as any of several million colors, and when all the pixels are placed in the correct order, they form an image.
The correct order and color of these pixels are often stored in a file on a computer. Image file types such as GIF, JPG, BMP, EPS, and others simply use a slightly different technique to describe the proper order and color of the pixels that make up a given image. Videos, which are a series of still images, are stored in formats that can support information for a soundtrack that accompanies the video.
Image files are saved in different formats. For still images alone, there are nearly 100 different file formats. Each format offers its own compression technique and image quality for a variety of practical applications. These are the most common file formats for still images and a brief description of their common usage.
To allow sharing of such a photo, one solution is to compress the photo data (data that represents the photo), which means rearranging the data and reducing the number of colors in the photo so that the data takes up less space. This technique is used by the Graphics Interchange Format (GIF) file format. The GIF format is the most popular digital format used to display images on the Internet simply because they have a lower file size and allow for faster downloading.
Although the GIF image appears less detailed than the original raw photo, as a result of compression and color reduction, the GIF image occupies only 68,000 bytes of storage. This size is a reasonable size for sharing the photo. To allow the exchange of more detailed image files, the developers of the JPEG format devised a more sophisticated way of compressing data. They realized that the human eye cannot distinguish all possible shades of color or all details; therefore, they developed a technique that reduces the colors and complexity of a photo without appearing to have done so. In other words, the only data removed in the JPEG technique is data that your eye would not process. The following image shows an example. As you can see, this photo is much more realistic than the GIF version and it takes up less storage space. Digital images play a very important role in website design, choosing the right format allows users to view your website quickly. Learn more about digital image formats and tips on how to build a website without programming knowledge or expensive software.