Archive for the ‘Image Editing’ Category

Exercise 8 – Filters

Saturday, November 15th, 2008

texture-cube.pngMost people are familiar with the concept of filters, in fact unconsciously used them many times. Everytime you sharpen an image or apply a gaussian blur, every single pixel gets processed by a certain mathematical rule.

This post demonstrates a few well known filters and reveals the magic of what goes on under the hood.


Exercise 7 – Colors

Thursday, November 6th, 2008

This week’s post is all about colors and how you can use code to work with them. We create a color picker and apply color filters to an image to create a neat effect.


Exercise 6 – Pixel editing

Thursday, October 30th, 2008

According to Wikipedia, “Image editing” encompasses the processes of altering images, whether they be digital photographs, traditional analog photographs, or illustrations. In our case we alter digital photos and those consist of pixels. Learn more about how to manipulate pixels and techniques to overlay several images.


Exercise 5 – Image manipulation

Thursday, October 23rd, 2008

In times of Photoshop you can never be sure whether a picture really reflects reality or is just a well-done fake. And then there are real pictures you would never believe aren’t manipulated. 

This post also looks 10 years into the future and tries to guess how I might look then.


Exercise 4 – Image composition

Wednesday, October 22nd, 2008

Learn how to create a stunning result by composing multiple images in Photoshop.


Exercise 4a – GIMP

Thursday, October 16th, 2008

Task 1: Replacing backgrounds

We start with a basic picture with a rather unexciting background.


We use the Fuzzy Select Tool (Photoshop users would refer to it as “the magic wand tool”) to select our background. Holding down the shift key adds further areas to the selection. 

When we are happy with it, we create a new layer mask by right-clicking on our background layer and choosing Add Layer mask … We want our selection to be the layer mask.

We’re almost done! The last step is to copy our new, shiny background into the picture:

Tadaah! The result looks as follows:

Task 2: Aurora Borealis

There is a great step-by-step tutorial on how to create a “Mac OS X Leopard”-like Aurora Borealis effect:

Here my result:

Task 3: Red Eye Removal

A very common task in the field of image editing is red eye removal. Most image editing programs include pre-defined RER filters. In this example, I show you how to use GIMP’s Red Eye Removal Tool and how to further improve your image.

Here is the picture we want to edit:

In GIMP, the feature to remove red eyes is under Filters -> Enhance -> Red Eye Removal …. Just applying this filter would not do the trick in this case. The color of the whole image would be altered. So we select each eye with the Ellipse Select Tool and create a layer mask for just that eye.  

Now we can apply our filter to both eyes individually which gives as a lot more flexibility.

But even with that done, the right eye still looks brighter than the left one. So we adjust the color by going to Colors -> Hue-Saturation until both eyes look similar.

Here is my final result: