GIMP Quickie No. 4 – Creating Color Pop on Midtone Grayscale

The following steps are for GIMP 2.8.

Step 1

• Load image into GIMP and crop as desired.

Original Image
Canon EOS 5D Mark III at f/4, 1/160 sec, ISO-100, 200 mm

Step 2

• Duplicate layer.
• Colors > Desaturate
• Luminosity
• OK
• Rename new layer to "Lights".

Luminosity Desaturated Image ("Lights")

Step 3

• Duplicate "Lights" layer.
• Colors > Invert
• Rename new layer to "Darks".

Inverted Luminosity Desaturated Image ("Darks")

Step 4

• Change Mode of "Darks" layer to Difference.
• Right-click in Layers dialog > New from Visible
• Rename new layer to "Mids".

Midtones Image ("Mids")

Step 5

• Copy "Mids" layer. (CTRL+C)
• Hide "Lights", "Darks", and "Mids" layers. (Turn off eyeballs.)
• Duplicate original image layer.
• Rename new layer "Curves". (It should be above the original image layer.)
• Right-click on "Curves" layer > Add Layer Mask
• White (full opacity)
• Add
• Make sure mask is selected (white border around right icon).
• Paste "Mids" copy. (CTRL+V)
• Anchor Floating Selection (Pasted Layer) onto mask. (Anchor symbol at bottom of Layers dialog.)
• Select non-mask part of "Curves" layer (white border around left icon).
• Colors > Curves
• Adjust curves to taste. (Note that only the midtones change because of the mask.)
• OK

Curves-Adjusted Image

Step 6

• Unhide the "Mids" layer.
• Right-click on "Mids" layer > Add Layer Mask
• White (full opacity)
• Add
• Select the Paintbrush tool (P) with a Hardness 050 round brush.
• Make sure the mask is selected (white border around right icon).
• Set the Foreground and background colors to black and white (D).
• Paint black over the areas where you want color to show through.

Mask

Color Pop on Midtone Grayscale

Step 7 (Optional)

• Copy the mask on the "Mids" layer. (CTRL+C)
• Hide the "Mids" layer.
• Unhide the "Darks" layer.
• Right-click on the "Darks" layer > Add Layer Mask
• White (full opacity)
• Add
• Make sure the mask is selected (white border around right icon).
• Paste the "Mids" mask onto the "Darks" mask. (CTRL+V)
• The "Darks" layer Mode should still be Difference.

Color Pop on Altered Colors

Acknowledgements

Special thanks to Pat David for his Luminosity Masks tutorial. This is my currently favorite way to enhance contrast and colors in images.