Background Repair w/ PhotoShop

 

Although this tutorial uses PhotoShop, this technique will work with any image processor, such as Paint Shop Pro, that can use layers and has a noise generation function.

 

 

This process can be used to smooth noisy irregular backgrounds and remove gradients. The above image has both of these problems. The gradient runs from the upper right to the lower left. This is accomplished by simply replacing the background with an artificial one. Here's how to do it.

*****************

First, use PhotoShop's' eyedropper to find the darkest pixel value in the background... in this case it's 25. Next create a new image, exactly the same size, and use the paint bucket tool to fill it with level 25. This will be the base for the new background.

*****************

 

Now paste the "background base" onto your image as Layer1, set the blend mode to Lighten, and make layer 1 active. Next, use the Brightness/Contrast tool to brighten Layer1, just until you are about to loose background details. Now you have an image with a smooth, but plastic looking, background.

*****************

The final step is to add some monochromatic noise back into the background, to get a natural look. I find a value of two to three works best. Also, experiment with both uniform and gaussian distributions. After adding the noise, a final tweak of the brightness of Layer 1 may be required, before flattening to the finished image. I find that the new background needs to be darkened a bit after adding the noise. Now the final image, above, has a smoother background and the gradient is removed. I hope you find this process useful and happy processing.