Color Correction and Restoration - Beginning Photo Retouching and Restoration Using GIMP - page 108

Figure 4-50. Adjusting the levels in the Red channel

12. Select the Green color channel and move the black point slider to the right, until

the value is about 30. Move the white point slider to the left, until the value is
about 218. The midpoint slider should be set to around 1.17 (Figure 4-51 ). Wait
until you adjust all three color channels before clicking OK.

Figure 4-51. Adjusting the levels in the Green channel