Getting a white background

Studio portraits are a very common image we print at CC Imaging. Occasionally, we receive images with a colour cast in the white areas which needs to be corrected before printing.  This guide will run through one of the easiest and quickest methods of getting a white background.

1) Here is an image we have just opened in Photoshop (CS). You can see a strong Cyan cast in general.

2) The first thing to do is pick a white point.  Open the Levels pallette (apple+L or Ctrl+L) and click on the white point eye dropper.

3) Now move your mouse over the background on the image we need to turn white and click the mouse.  Then press OK to Levels.

4) It is likely that your image is now burnt out (very white).  As long as the background is a good even white this burning is not a problem.

5) Open the History pallette and to the left of the layer name you will see an empty square.  Clicking this will set this history step as the one used by the History Brush.  As we have only opened the image and set the Levels the history step we need to choose is the one above Levels.  Selecting Levels history step will NOT make a change, so select the one above.

6) Select the History Brush tool by pressing the Y key on the keyboard.  Make sure you set the brush Opacity and Flow to 100%.  Use this tool to 'paint' back in a previous history step.  Below you can see dark areas in the bean bag, this is where we have painted in the previous history step ontop of our image.  It is similar to using the paintbrush and you should be careful to stay inside the edges of the people and avoid painting on the now white background.

7) We have successfully made the background a good even white, now we need to remove the colour cast from the people in the image.  To do this we will open the Colour Balance pallette (Apple+B or Ctrl+B on the keyboard).

8) Using the sliders, add red (move top slider right) and yellow (bottom slider left) until the image looks a warmer more neutral colour.  Now click OK on the Colour Balance pallet.  As you can see, our finished image has a good clean white background and the colour of the people is much better.