PMC Editing Wiki: Tools GraphicsMagick

2022-04-11T03:09:00Z

-modulate brightness[,saturation[,hue]]

Vary the brightness, saturation, and hue of an image.

Specify the percent change in brightness, color saturation, and hue separated by commas. Default argument values are 100 percent, resulting in no change. For example, to increase the color brightness by 20% and decrease the color saturation by 10% and leave the hue unchanged, use: -modulate 120,90.

Hue is the percentage of absolute rotation from the current position. For example 50 results in a counter-clockwise rotation of 90 degrees, 150 results in a clockwise rotation of 90 degrees, with 0 and 200 both resulting in a rotation of 180 degrees.

Source.

First de-saturating and then darkening or just doing both at the same go has no difference, image looks the same in both.

ArmA 3 terrain PMC Mongolia saturation values for satellite texture.

rem gm convert -modulate 100,80 Mongolia-arcigs-16-level.png _deleteme_test_saturation.png
rem gm convert -modulate 70,80 Opteryx.Edited.Satellite.Texture.Tiles.DO.NOT.DELETE.2019-08-27\sat_a1.png Sat_A1_Darkened_Saturated_test-01.bmp
rem gm identify -verbose Sat_A1_Darkened_Saturated_test-01.bmp
rem gm identify -verbose Sat_A1_Darkened_Saturated_test-01.png
rem gm convert -limit threads 7 Sat_A1_Darkened_Saturated_test-01.png -resize 2048x2048 GraphicsMagick-Darked-Saturated-Test-01.png
gm convert -modulate 70,80 Opteryx.Edited.Satellite.Texture.Tiles.DO.NOT.DELETE.2019-08-27\sat_g2.png Sat_G2_Darkened_Saturated_test-02.png