Brighten up dark photo colors with Gimp

This tutorial is a help to increase brightness of dark photos and images with Gimp. You can use Gimp to lighten, correct, adjust, enhance and improve the brightness of a dark photo portrait.

Author Moris Garon for Gimps.de with Photo Software Gimp.

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Brightening dark photos is good !

A beautiful photo with too much darkness makes any professional photographer upset. The dark photo is hiding it's dark secret by reflecting colors in bad brilliance of low brightness and contrast being too pale, too dark, too blurred or just fuzzy.

Fortunately a good digital camera is saving brightness of color very exact, even if the luminosity of natural lighting is too dark for a perfect photo portrait. Photographers lighten dark images manually with a photo editing software in order to fix or correct brightness of color in underexposed photo pictures.

A good digital photo editing software can improve, enhance and adjust brightness of color in any underexposed image or picture.

Gimp is a free photo software,

a program and a digital photo flash for brighten up an image in Gimp's photo studio. You can use Gimp to lighten the color of eyes, teeth, skin and hair of a face in a photo portrait.

Guide and help for brighten up dark image with Gimp

lighten dark photo colors automatically


#1 create a brightening layer

Duplicate the original image layer in the layers dialog. Change the Mode of this duplicated layer to Value -mode to use this layer for a retouching brightening of colors. Further editing of the image, without this masking layer , could lead to a change of original hue and colors within the picture.

#2 improve brightness

Apply the Tools » Color » Levels -dialog to the retouching layer for manual or automatic correction of brightness, color and contrast. Click on the Auto Correction -Button in the levels Dialog to try Gimp's automatic correction of brightness, color and contrast.

#3 check color change

Switch off the visibility of the first original layer of the image to check the change or difference in colors of the retouching layer.

If the hue and colors of the original layer affect the image badly you can just delete the original layer.

Otherwise combine all layers in the image or try the manual brightness correction, if the automatic correction did not work for your image.

Correct colors and brightness manually

As a good photo software Gimp allows you to correct the brightness manually. Use the Tools » Color » Levels -dialog to enhance, fix or improve brightness of colors manually.

The sliders on the scale of Output levels can adjust the brightness or darkness for each color channel in the image.

Shrink the distance between sliders on the scale of Input levels to adjust the contrast and lightness of a color channel in the image. The middle slider for Gamma can be used to correct hue of each color channel in a picture. Example : Should the image contain too much of red color, then decrease the value of Gamma for the red color chennel.

Brighten dark shadow in a photo

The darkest secret of an image is in it's shadow. Good shadows can build a positive contrast of light and dark that helps to discern contours in a low-key photo. Bad shadows hide details and contours in a photo portrait.

Gimp can clear the dark haze of shadow with a Contrast Mask, if the contrast of light and dark goes too deep into darkness. The following guide is a help for brightening shadows in an image.

#1 desaturate, invert and blur colors

Duplicate the lowest original layer of the image. Change the Mode of this duplicated layer to Overlay, for using this layer as a retouching Contrast Mask.

Use the Layers » Color » Desaturate tool to remove the saturation of colors in the retouching Contrast Mask. Use the Layers » Color » Invert tool for inverting the brightness in the desaturated, colorless Contrast Mask.

Blur the desaturated and inverted Contrast Mask with the Filters » Blur » Gaussian Blur -filter. I used a radius of 15x15 px for blurring the "Contrast Mask Layer" in my image.

#2 mask the retouching Contrast Mask

Use the Layer » Mask » Add Layer Mask -dialog, for adding a semi transparent Layer Mask to the shadow correcting Contrast Mask to make the effect of retouch more diffuse, soft and photo(no) natural. Use the setting Grayscale copy of layer as the layer mask type.

Tip: You can duplicate the layer with the Contrast Mask to brighten the shadow in the image even more.

#3 save original hue and saturation of the image

Duplicate the lowest original layer of the image. Move the duplicated layer to the top of all layers and change the Mode of this moved layer to Hue -mode, for keeping the hue of colors natural to the original image.

Duplicate the upper, hue saving layer and change the mode of this copy to the Saturation -mode, for keeping the saturation of colors natural to the original image.


A photo before and after lighten up with Gimp.

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