Add a gamma slider
My scanner doesn't have any option to adjust brightness or contrast but it can adjust the gamma value. It would be really useful if you added a slider on the same place as the brightness slider :)
In case you need it, here is some debug info:
Option 9: name='gamma' title='Gamma function exponent' type=fixed size=4 min=0,299988, max=5,000000, quant=0 cap=soft-select,soft-detect,automatic
Device: name="pixma:04A9178A" vendor="CANON" model="Canon PIXMA MG3600 Series" type="multi-function peripheral"
Also, you can directly adjust the gamma with the command scanimage --gamma X.XXXX
Edited by Ghost User