This GIMP (GNU) tutorial demonstrates how to Remove Red Eye. To work along, you are welcome to download the photograph I am working with Here. Unzip the file and open the Start Image onto GIMP’s workspace.
Remove Green, Blue, Yellow Flash Eye From Animals
General Flash Eye Notes
Redeye (green, yellow or blue eye for animals) occurs when a photograph is taken with a flash. Light from the camera’s flash is reflected onto the retina at the back of the eye, and in humans, (and sometimes dogs) results in red eye, caused by the blood vessels. Animals; including, dogs and cats, have special reflective layers (tapetum lucidum), over their retinas - similar to mirrors, and this aids their nocturnal vision. This results in the strange green/yellow/blue eyes often displayed in photographs of indoor pets, (taken with flash). As they age, their eyes become cloudy, exacerbating the spooky appearance caused by flash.
You can quickly Undo a step at any time by pressing Ctrl then Z. Alternatively, click a previous Undo History snapshot - Windows then Dockable Dialogues then click Undo History. In addition, to Zoom in (or Zoom out) of your image; from the top menu choose View then select a Zoom Tool from the subsequent
Launch GIMP & Organise Its Workspace & Palettes
Open your choice of Start Image onto GIMP’s workspace - File then Open - Ctrl then O.
Duplicate Your Image
It’s important to preserve your original image: therefore, Duplicate your image; Ctrl then D - (Image then Duplicate). Now, close the original image, and work on the Duplicated image.
For accuracy, Zoom into the eyes: - top menu, then View then Zoom.
Shift+Plus Key And Minus Key Tip
To quickly zoom in or out of an image - tap your Keyboard’s Shift+Plus Key or the Minus Key, respectively.
I zoomed in three times.
You are looking to isolate both Red Pupils with a Circular Shaped Selection Marquee.
Now, from the left-side Toolbox, activate the Ellipse Select Tool.
And enter the following Add to current selection settings into the Options Box.
To constrain the Elliptical Selection Marquee into a circle: press your Keyboard’s Shift Key - and simultaneously draw out your Elliptical Selection Marquee, it will then be constrained into a circle.
Now, left-click and drag out a Circular Shaped Selection Marquee over the
left-side pupil - as illustrated below.
Then Resize, and Reposition the Selection Marquee so it tightly hugs the red pupil.
My Tutorial Here (Chapter 4) Demonstrates How To Resize/Reposition The Marquee.
Left-click outside the Circular Selection Marquee to complete the application.
Then left-click and drag out a second Circular Selection Marquee, this time around the right-side pupil - as illustrated below.
And resize the Circular Selection Marquee so it isolates the Red Pupil tightly, just as you did with the left-side Circular Selection Marquee.
Remember to complete the application by left-clicking outside the Circular Selection Marquee.
Now you have isolated both red pupils with a Circular Selection Marquee, you are ready for the next step.
3/ Feather The Selection Marquees
To Feather the Selection Marquees’ edges, right-click over one Selection Marquee, and from the subsequent drop-down list, choose Select and then choose Feather.
Then, from the subsequent Feather Selection dialogue box, set a Feather selection by value of 2 (Pixels), and then click OK.
From the top menu, choose Filters then choose Enhance and then choose Red Eye Removal. And from the subsequent Red Eye Removal dialogue box, enter the following Threshold 100% setting, or experiment, and then click OK.
Now, to further darken the Selected Pupils, from the left-side Toolbox, activate the Dodge/Burn Tool.
Then set the following Burn settings into the Options Box.
You can quickly alter the Brush Size by tapping your Keyboard’s Square Bracket Keys.
Now, darken the pupils by left-clicking and applying the Burn Tool inside both Selected Pupils - as illustrated below.
Reapplying the Burn Tool will increase the darkening. Therefore, be careful not to over-darken the pupils. If necessary, tap Ctrl then Z to step backwards.
Now, from the top menu, choose Select and then choose None.
If necessary, you can minimise any stubborn red pixels using the Burn Tool.
I changed the Burn Tool’s Brush from Hard to Fuzzy, and I also changed the Range from Midtones to Highlights.
Return your image to its original size; View then Zoom then Zoom Out.
Congratulations, your red eye removal work is complete, and it is ready to save - top menu, then File then Save As.
Now you are familiar with this technique, you can have lots of fun removing red eyes from your favourite images.
Wendi E. M. Scarth. Top of Page.