Choosing a Format for Your Pictures -- jpg, gif, png or bmp

If you have ever wondered about what format to save your pictures in, this is a little exercise to help you see the difference in size and quality of the formats. The formats are png, jpg or jpeg, gif, and bmp. You can Google the terms to get a technical explanation. This is just a visual showing and size comparison. You can click on each picture to enlarge it to judge its quality. Each picture is the same size and resolution, but was saved in a different format.

The first photo below is a png. It is of a good quality. It's size is relatively large -- 762 KB (only bitmap or bmp was larger).

.png example

The picture below is jpg or jpeg. It is the most common on the web. It is considered a "lossy" format where some quality is lost. The image was saved at 100% and it's size is 414 KB.

.jpg example

Below, you will find a gif image. It is not stored as RGB, but rather colors indexed to a palette. It is compact in size at 256 KB, but it's quality suffers a bit compared to png, 100% jpg and png.

.gif example

The last pic is a bitmap. It has the largest size of all of the formats at 1,370 KB.

.bmp example

So if you are worried about disk space, you would want to save your pictures in the jpeg or gif formats.

Incidentally, the flower is a tropical one. I don't know the name, but I took the photograph in Nassau, the Bahamas.

Experiment on JPEG Photo Quality

As I play with photos in Gimp and Photoshop, when I save JPEG's it asks me what quality (expressed in a percentage) that I want to save the picture as. JPEG is a "lossy" image compression scheme, meaning that the image is stored as compressed, and when it is uncompressed for viewing, it isn't exactly true to form. Some of the detail is lost. I decided to run a test to see what the losses look like.

I thought that text would be the perfect medium to graphically see the change in image quality. I thing that I may have been wrong. Maybe a crisp image of a tree with lots of branches would be better, or a crowd picture. I will try these when I get time. However, here is the text pic comparisons:

This is 100% quality:

This is 80% quality:

This is 50% quality:

This is 20% quality:

This is 10% quality:

The image is of a sign at the beach of the One and Only Ocean Club golf course. I usually save my pictures at 90%, but I think that I will start saving them at 100%, except for the quick and dirty ones.