Using Photoshop actions in GIMP

GIMP#, a project to provide a “C# wrapper around the GIMP API” and that “enables users to quickly write new GIMP plug-ins using .NET or Mono” has had some exciting developments recently.

Maurits is working on a GIMP# plugin that will hopefully allow GIMP to use Photoshop actions. AFAIK, these are basically files with calls to Photoshop functions. They are self-contained programs using a Photoshop programming API to perform operations on images. There are a countless number of Photoshop actions for download, free, shareware and commercial, so having access to these plugins would give GIMP a huge boost in terms of what it can do.

There are problems, some filters and functions in Photoshop simply aren’t available in GIMP but he has managed to parse 25 filters from the action files.

Lots of actions map on a GIMP equivalent. I downloaded about 100 action files and created a top 25 of most often used functions. At the top are functions like Brightness/Contrast, Set Selection, Gaussian Blur, etc. etc. The first function without a direct GIMP equivalent is the Chrome filter.

Simple steps to photo touch-up

In this post I’m going to show you how to go post-process this image:
By the end, we’ll have an image that looks like this:

This tutorial was created using the GIMP, but it’s equally applicable to your favourite editing software as long as it has the same tools. Photoshop, and other editing software should work equally well.
The steps described here are worth practising, and will apply equally well to any portrait!

First of all, I came across this photo on Flickr through my contacts page. Here’s the original photo, and Ayhtnic kindly let me use her image.

After you load the image, the first thing to do is use Auto Levels from the Layer->Colors menu. This tool alone does wonders for most photos, especially if they’ve been captured as Jpeg straight from the camera.

The image is a little noisy so let’s clean it up a bit. Use Selective Gaussian Blur from the Filters->Blur menu. Use small values as we just want to smudge the noise away without losing too much detail. A radius of 3, and delta of 10 worked fairly well here.
Let’s brighten it a bit and add contrast. Use the Curves tool from Layers->Colors for this. The classic “S” shape always adds life to a photo.
Open the Layers dialog and duplicate the background layer.
Select the new layer (called “background copy” here) and use the Curves tool again to brighten this layer a lot.
With the same layer selected (the top one, the “background copy”), we’ll apply some blur. Open up the Gaussian Blur tool, it’s in Filters->Blur. Apply a blur of 5 pixels to the top layer. Don’t worry, we’re not finished!
We’re going to change the “mode” of the top layer now. With the top layer selected, click on the drop down box that says “Normal” and scroll down to “Soft Light”. You can also try other modes, they’ll make for interesting photos!
Notice how the image suddenly changed?
Even with the nice glowing effect, the image looks indistinct. Let’s sharpen the bottom layer. Select that layer in the Layers dialog and load the “Unsharp Mask” filter. This is in Filters->Enhance->Unsharp Mask.
Don’t apply too much sharpening. Make it subtle. The settings in the screenshot work well.

All that’s left is to save the image, save it with a quality setting of 92%. Don’t bother with higher as it’s practically impossible to see any difference in quality.


The finished photo

Noise Reduction the Open Source way

What are your options when you don’t run Windows or Mac and/or don’t want to use proprietary software?
Niklas Saers covers some of the options in this blog post. Thanks to him, I learned about ISO Noise Reduction, a GIMP plugin, which I’ll give a try tomorrow.
I usually use DCAM Noise, or selective blur to remove offending pixels but that can leave awful looking smooth areas next to unsightly pixels.