Getting Started with Image Editing

If you're new to image editing getting started may seem daunting. This free lesson offers an introduction to put you at ease.

Image file formats

There are many different file formats images can use. It's important to understand the basics of image file formats, along with the most common ones you'll see when working with images.

File size and image compression

Digital image files can be very large and take up a lot of hard-drive space. Because of this, many file formats use compression in order to reduce the file size. There are two main types of file compression:

Images that use lossy compression can be saved at different quality levels. The lower the quality, the smaller the file size—that's because lowering the quality also removes more information from the image. In the example below, you can see the same image saved at different quality levels:

image comparing vary levels of image degregation and quality

Drag the slider in the interactive below to adjust the compression quality. Remember, higher quality levels will also increase the file size. Try to find a setting that looks good while keeping the file size relatively small.

Recommended file formats

These are the most common file formats. We recommend using them most of the time:

Other common file formats

There are many other image file formats you may encounter. One common image format is GIF. Pronounced "gif" or "jif", the GIF file type was originally designed for graphics, but it's now most commonly used for simple animated images for the web. For example, the image below is an animated GIF file.

an animated GIF image

There are also some file formats that do not use compression, such as RAW and BMP. For example, some digital cameras use a RAW format to save very high-quality images. Because these formats are uncompressed, the files tend to be much larger than JPEG or PNG files.

Keeping your originals

Whenever you edit an image file, there's a chance some of the original information from the image can be lost. Also, if you edit the same file over and over again, the edited image can begin to look much worse than the original. This is called image degradation, and it's especially problematic for files that use lossy compression, such as JPEG images.

The good news is there's an easy way to avoid this problem. If you're planning on making even basic changes to an image, such as cropping or resizing, you should also keep an original, unedited version of the file. We recommend making a habit of doing this whenever you're working with image files. This way, you'll always be able to go back to the original version.