Lilahpops

Create a cool green colour effect with curves

Cross processing is something I have started to experiment with. I find I’m drawn to many of these photos on Flickr - the effect can be quite stunning. I uploaded the final cross-processed result of this image to Flickr and it made Explore soon after.

Here we’ll focus on the green effect you can produce, although you can also adjust your settings for other hues, such as red.

It’s all about the curves

Cross processing can be a very simple GIMP edit if you set and save the RGB colour curves to your GIMP library. You can then re-use the setting again and again with other images. I have a few of these options saved in my GIMP library: one is a general curves adjustment; one boosts each RGB colour channel for retro effects; and now I have a green cross process setting.

Save the setting the first time you use it and it will then be available for future edits.

Auto-levels

In the image above I did a quick auto-levels adjustment Colors -> Levels -> Auto. I played around with the Hue-Saturation and Contrast options but decided to not to use these changes as there is quite a lot of contrast already. It will depend on your image if you need to boost the colour and contrast.

Save your curves setting

Now to the curves. Go to Layer -> Duplicate Layer - a handy option as you can simply delete the layer if you don’t like the results. The settings below are what I have come up with after reading a bagful of articles about cross processing.

Select Color -> Curves and change the individual RGB channels to the settings below:

Red setting

Green setting

Blue setting

Select Save and name your curves something useful, like Cross Processing - Green. You can use this setting for other images you cross process without having to change the RGB values each time. To access your saved files next time simply go to Color -> Curves -> Open.

Click OK and the image now looks like this:

You can also add an almost transparent fill layer of a lime green (to bring out more green) or a fushia (to bring out more red and blue). I’ve decided against a fill layer with this particular image.

Crop and you’re done

I cropped the balcony out of the image which brought more focus to the sky and those gorgeous sunbeams.

Et voila! Click the image to view a larger size in Flickr.

Related cross processing articles

• Brian Auer has a great tutorial on both green and red cross processing over at Epic Edits Weblog
• Check out the impressive results by Danny Ngan at Poo-Poo Platter

Other examples

It’s interesting to see the various RGB settings that are used and leads me to think I should make save a few more curves settings saved to my library.

Here are some other images I have cross processed - with varying degrees of success.

Do you have any handy cross processing tips?

See also:

• Give your photos a retro feel with the GIMP
• Saturate the colours in a photo with GIMP

A curves adjustment can dramatically change the look of your photo

I took this photo the other day on my way home from work.

This friendly fellow was hanging about with his horse pals under the tree in the background to the right. That was going to be my composition, some horses crowding into the shadows of the tree to escape the glare of the sun. But as soon as the horses saw me at the fence they decided to come over and say ‘Neigh‘.

I had the camera on auto settings, the only change I made was to set the macro. Being a lovely rural area I wanted to give it a more country feel. The result ended up looking quite ‘retro’. So, “Bring out the GIMP!” and let’s get started.

A quick word about GIMP

I have written previously about the GIMP here. GIMP is similar to Photoshop but it’s free. You can find out more about it and download your own copy at the GIMP Website and there is a manual available at GIMP Documentation. I found the following post extremely useful in downloading GIMP for Mac:

• How to install GIMP on Mac OSX

Saturate the colours

The first thing I did was a quick auto-levels adjustment at Colors -> Levels -> Auto. Then I bumped up the saturation at Colors -> Hue-Saturation and moved the saturation slider up to 50.

Now for the curves adjustment.

Go crazy with curves

I’m relatively new to curves and have recently been experimenting with the color channels. I followed the advice at Layers magazine on boosting the individual RGB color channels.

See the difference each change makes to the image:

Red color channel

Green color channel

Blue color channel

Tighten the image with a crop

A quick crop, making sure to keep the fly-away hair of the mane intact.

Almost done. The image is now too saturated so back to Colors -> Hue-Saturation and move the saturation slider down to -20. Experiment with the different saturation and curves settings for the best results.

Et voila! Click the image above to view it at a larger size in Flickr.

Save your image

I have been saving the image in the its native GIMP .xcf format and then saving a .jpg copy to load to Flickr. To save it as a .jpg or .png etc go to Image -> Flatten image and then choose File -> Save As …

Related posts

• Saturate the colors in a photo with GIMP
• How to resize an image in iPhoto
• Add special effects to your images with iPhoto
• Use the tools in iPhoto to edit your images

GIMP has almost as many features as Photoshop but it doesn’t cost the earth.

I visited the Leuralla Toy and Railway Museum the other week and took this photo of an old warning sign.

It’s amusing but it needs some work, right? Being an old-fashioned sign I wanted to add a vintage feel to it. I also wanted to bring out the red in the paint to exaggerate the warning itself. This is where you can yell “Bring out the GIMP!”

Before exporting the image from iPhoto I gave did a quick crop and straighten.

That’s better.

Saturate and contrast

Next, I opened the image in GIMP and selected Colors -> Hue-Saturation and increased the saturation to 100. I also selected Colors -> Brightness-Contrast and increased the contrast to 40.

Now the text of the sign stands out and the red is nice and bright.

Add the vintage effect

Lastly, I added a vignette to give it a more vintage feel. I followed an excellent tutorial at gimpology.com on creating vignettes to do this, so I won’t repeat the steps here. (Note: I didn’t complete the last step of this tutorial which was to add a transparent magenta colour layer over the whole composition.)

And here is the final result. Click the image for a larger size in Flickr.

Makes you think twice about littering.

Try GIMP yourself

GIMP is my new favorite editing tool.

If you’d like to try out GIMP you can download it from the GIMP Website and there is a manual available at GIMP Documentation. I found the following post extremely useful in downloading GIMP for Mac:

• How to install GIMP on Mac OSX

Related posts

• Give you photos a retro feel with the GIMP
• How to resize an image in iPhoto
• Add special effects to your images with iPhoto
• Use the tools in iPhoto to edit your images