- Altering brightness has nothing to do with the printer model.
- Altering brightness has nothing to do with the PPD (drvless or HP).
- The only files that can be made brighter or darker are image files (jpg etc).
- cups-filters has imageto... filters to manipulate images (e.g. imagetopdf).
- A PDF cannot be made brighter or darker.
- Most applications produce a PDF to send to the printing system.
- The printing system by itself cannot convert a PDF to image format. It needs help.
- Tea4CUPS can help if a user devises a script to use with a hook.
Definitely! In my next post I will give you a command to use as part of a script.If I understand right, it would be possible in principle with "Tea4CUPS" and with a "script that must be written first". (?
These are options understood by imagetopdf:
- brightness. The default is 100.
- gamma. The default is 1000.
- saturation. The default is 100.
- hue. The default is 0. The range is -360 to 360.
- colorspace. rbg, cmyk or gray.