Gimp - Correct color levels
Introduction
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This tutorial will help correct the color levels of a photo.
It will allow you to specify where's on the image are the whites, blacks and grays.
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Loading an image from the hard-drive
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From Gimp file menu, open your source picture.
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Levels correction
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From the Colors menu, choose Levels.
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In the window that opens, click on the left eyedropper to select the black level.
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Then click on the darkest point of the image. Gimp will know where is the most black point to correct the image color.
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Repeat for the white (right pipette), then, if necessary, the gray (middle pipette).
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In the levels window, click OK. The colors are now corrected.
Corrected photos examples
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Those images were taken behind a window. Bland colors are corrected.
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