Scanner's contrast setting. 0x0501 ∙ 1281
IG_ISIS_TAG_CONTRAST sets or reads the contrast setting of a scanner.
IG_ISIS_TAG_TYPE_SHORT
All scanner drivers.
A value of IG_ISIS_TAG_CONTRAST_AUTO (0) means automatic contrast control or that no contrast control is available. A value greater than zero indicates a specific contrast setting. Higher numbers mean higher contrast.