Differences between JPEG, PNG and GIF files

     There is a multitude of ways in which an individual can save image files. In this week's set of Lynda tutorial videos, I learned about the most common image file formats and how to save them as such in Adobe Photoshop. For this blog post, I wanted to explore the ways in which JPEG, PNG and GIF files change the way a semi-transparent cloud is depicted post-save.

     This is an example of a JPEG image file. JPEGs are flattened files, which means that they do not support layers, or transparency. They are also compressed and utilizes lossy compression. Lossy compression is when the formatting software selectively discards, or throws away, information data of the image. The amount of information that is thrown away depends on which quality is chosen to save the file. JPEGs are often used on the Internet for posting to websites and for sending in emails and text messages.

     This photo is an example of a PNG file. Similar to JPEGs, PNGs are flattened files, however, it supports 256 layers of transparency. Therefore, PNG files are great to use for businesses and for creating logos because watermarks can easily be added onto them. As you can see in this image, some of the lighter shades of gray and are less visible than in the JPEG file. Quality-wise, they are pretty similar. 

     This image is an example of a GIF file. GIFs are most often seen as animation-style images. They are flattened, compressed files and they use lossy compression, much like JPEG files. Like PNG files, GIFs have some form of transparency, but it's not as freely used as in PNG files. GIF files compress their file so they are only able to use 256 colors within the image. Therefore, before saving, the software has to convert any unknown colors into "blanks". Also, transparency can only be used for one of those 256 colors, and transparency will only save with one layer, so you will often see pixelization or jagged edges if it is on a curved edge, like you see in this image of a cloud.