How to change the background color of an image?

Question

This is the front page of my project. As you can see there is an image and a label 'C-MARK CALCULATOR'.

I want to make the white portion of the image to black, that is the background color of the window. How can I do it ? Can I do it using Picasa or Paint ?

Answer 1

What you need to do is create a second layer with the same color as the background. Place this layer behind your image, and then set the layer with your image to be Multiply. This will make both blend without any visual problems. I'm not sure if paint.net supports these actions with layers, but both Adobe Photoshop and Jasc Paintshop Pro will do this without much problem.

Answer 2

you need to edit the photo with a photo editor e.g. Photoshop or Paint.NET. There is a tool in both of them called Magic Wand, then use it to select the white space and press DEL. The procedure in a video, HERE.