Share your GIMP tricks and tips

[Sagadin]

I thought it might be nice to exchange tips on using GIMP to enhance photos. I know that there are various tutorials out there on the web but SL specific ones might be useful here.

I'll start with a few screen shots showing a technique I use all the time for making colors more vibrant on otherwise "flat" photos. I selected a rather dull looking photo to start just to give you a sense of how the technique works. I learned this technique from a video I have since lost track of a couple of years ago.

First start out by adding a DUPLICATE LAYER to your rather dull shot:

 

Next change the new layer's MODE to OVERLAY:

 

From the COLORS menu select CURVES (note how dark your image looks with the top layer in overlay mode -- not to worry the next step fixes that):

 

Adjust the color curve as you see fit by clicking on the diagonal line and dragging it around. This affects only the color levels of the overlay layer. It may take some trial and error to find a balance that you like. But you can see how much better the original image now looks. All of the colors end up much more alive and vibrant. Make sure you click OK when you are done

 

. You can easily see the difference with and without the overlay by clicking on the eye icon which turns on and off each layer. If you like you can adjust the opacity of the overlay layer to moderate the changes -- less opacity means more of the original image shows through.

 

Well that's a simple trick to enhance photos. Anyone have other techniques to share?

 

 

 

[Saravendi]

I never work in curves... thanks!!!

[Saravendi]

What does GMIP stand for???

[Nalates Urriah]

GNU Image Manipulation Program - Google is your friend... LMGTFY ?

[Sagadin]

And of course GNU stands for "GNU's Not Unix." 

[Saravendi]

I’m totally Apple and PS... but programs seem to work similar:) thanks ?? 

[Amanda Dallin]

This is great.  I've used GIMP for years but only for textures.  I haven't used it to enhance photos.  I'd love to see more tips here.

[Tamara Artis]

I used gimp ages ago but even after transferring to PS I kept getting back to gimp for one reason and this was to cut out hair from the background. The photo I attached (it is from 2013. so excuse the outdated look) was taken against the plain studio background and I have cut out the hair using the feature named "color to alpha". Removing the bg in this way leaves the hair as it looks in-world. 

This works best with black hair and white background, but I managed to get nice results with other colors too. Here is the link that explains everything but also feel free to look up YouTube for some tutorials. https://docs.gimp.org/2.8/en/plug-in-colortoalpha.html 

 

 

[Sagadin]

Here's another quick tutorial on using layer masks which is very useful for applying effects to only part of an image.

1. Start out with a duplicate layer -- not strictly necessary but I find it helpful to do this since then I can change its opacity to "turn down" the overall effect of the new layer.

 

2. Apply an effect to your new layer. You can use a filter or change the colors or whatever you want. I am using the "glow blur" effect from the GMIC plugin set of add-on filters.

 

3. That's a nice effect but I do want my face to be a bit less blurry, so I'll add a layer mask. This will allow me to "cut holes" in the effect by painting on it with black. Right click on the top layer and choose "add layer mask."

 

4. The default layer mask is "white" or fully opaque. If you choose black instead the new layer will be completely transparent and you can "paint" the effect back in selectively using a white paint tool instead. Make sure to click "Add" in the layer mask dialogue box.

 

5. Choose a tool to paint black with. Here I am using the blend tool and its bi-linear gradient option which will create a black stripe fading to white on both edges. Click on the image and drag then release to set the two points defining the gradient. Dragging at an angle angles the gradient. If you don't like what you see just click again and you'll get a new gradient on the mask.

 

6. Here's the result. You can see the black stripe I made in the mask next to the top layer on the right of the screen.

 

You can use brushes or any other way of painting black on the layer mask to poke through it as you like. Just paint directly on the image, making sure that the layer mask is active by clicking on that little white box next to the layer with the mask. If you switch black and white in your color palette you can keep the mask opaque in the center and fade it off towards the edges of your image.

Have fun!

 

Edited November 4, 2018 by Sagadin