Monday, 27 March 2006

The different file formats

A while ago I had put up a post about how saving your pictures in different file formats can affect the overall quality and size of the picture. However that post was a little too advanced for a few people and I decided to make a simpler version. This one should be really easy since it only has the gist of things to make if easier for you to grasp certain key concepts. If you read through this you should have no problem in understanding the different file formats of how you can save pictures in and how they work.

Le'ts take a look at some most commonly use file formats here. Try to remember their full names might be handy in the future later on:
  1. JPEG- Joint Photographic Experts Group
  2. TIFF- Tagged Image File Format
  3. PSD- Photoshop Document
  4. GIF- Graphics Interchange Format
  5. PNG- Portable Network Graphics
Now let's take a look at how each of the formats work:

Joint Photographic Experts Group format:

As you can see in the above pictures, the original has more colours than the image named 'JPEG'. That's because, the JPEG format gets rid of similar hex codes.
This way the JPEG image has less codes to remember, so although the quality might be less, the size is going to be lower! That's basically all it does... so just a little tip, every time you save something as a JPEG it's quality will reduce, so if you keep saving it, you will reduce the quality of the image!

Tagged Image File Format:

What this format does is saves it just like the original, this means that the computer has more hex codes to remember, hence it has a bigger file size. But this is good sometimes, for example if you are not sending it you can preserve the original picture.

Photoshop Document:

This also works like a tiff format, however this format can maintain the images in layers, so that you can open up a application like photoshop and edit each layer individually. This can be very helpful while designing photoshop projects.

Portable Network Graphics:

This also maintains the quality of the picture like a tiff, however it mixes some of the hex codes to keep a lower file size. Another important thing about PNG is interlacing, which means that when the picture loads it loads in layers so you don't need to load the whole picture at once.

Graphics Interchange Format:

This is sort of like the older version of PNG, which takes away a lot of hex codes and doesn't have lot of transparency like PNG's. And although the quality might not be as bad as in the example, it does loose a little bit of hex codes and that's why they are used in web images and animations.

That's it... that's the basics of the file formats. If you really want to know more, then you can read this post. In that post I also talk about lossy and lossless formats, so you might want to know that as well!

Got a question, tip or comment? Send them to and we'll try to answer it in a blog post!

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