Open silviucc opened 3 weeks ago
What you call a "noisy" output seem to be shades of grey described via error diffusion. Your "clean scan result" is a simple black and white colour reduction.
Somewhere in your scanner driver (probably not in NAPS2) there must be a setting like error diffusion chosen instead of black and white. The setting "Bit depth: Grayscale" is not what you want: you want 1 bit images (black and white).
Hi. Below is the output of scanimage. It seems NAPS2 does not show all the modes supported by the driver.
scanimage -A
Output format is not set, using pnm as a default.
scanimage: rounded value of br-x from 211.9 to 211.881
scanimage: rounded value of br-y from 355.6 to 355.567
All options specific to device `brother4:bus7;dev3':
--mode Black & White|Gray[Error Diffusion]|True Gray|24bit Color[Fast] [24bit Color[Fast]]
Select the scan mode
--resolution 100|150|200|300|400|600|1200|2400|4800|9600dpi [200]
Sets the resolution of the scanned image.
--source FlatBed [FlatBed]
Selects the scan source (such as a document-feeder).
--brightness -50..50% (in steps of 1) [inactive]
Controls the brightness of the acquired image.
--contrast -50..50% (in steps of 1) [inactive]
Controls the contrast of the acquired image.
-l 0..211.9mm (in steps of 0.0999908) [0]
Top-left x position of scan area.
-t 0..355.6mm (in steps of 0.0999908) [0]
Top-left y position of scan area.
-x 0..211.9mm (in steps of 0.0999908) [211.881]
Width of scan-area.
-y 0..355.6mm (in steps of 0.0999908) [355.567]
Height of scan-area.
As I said: the setting "Bit depth: Grayscale" is not what you want. What other options are available for "Bit depth"?
Describe the bug
When scanning using grayscale I get very noisy output
To Reproduce Steps to reproduce the behavior:
naps2_grayscale.pdf
Expected behavior
It should output a clean scan result
simplescan_grayscale.pdf
Screenshots If applicable, add screenshots to help explain your problem.![Screenshot from 2024-06-16 11-48-27](https://github.com/cyanfish/naps2/assets/3889481/2e3052e6-d15e-4628-b4da-06bae2ab1af0)
Desktop (please complete the following information):
Additional context Add any other context about the problem here.
It may be a case where the scanner can do more grayscale scanning modes and simplescan is just selecting the one giving better results by default