Quote:
Originally Posted by japinder
Hi guys,
I need some help in converting a mixed color text+photo PDF to 16 shade grayscale & to trim the borders, headers & footers as much as possible, for viewing on my Onyx Boox M96.
The text has a color background, so the re-flow option creates grey colored strips of black text over a white background.
I gave up on re-flow & tried to do a simple grayscale + trim job, but although using the GUI, it shows the preview as black & white, the output is still color.
I switched to command line with the shortcut method, dropping the files on the shortcut already updated with the options. When I ONLY use the option -c-, then the output is grayscale, but re-flow occurs, with grey color strips of text. When I omit -c-, the output is still color. When I use any other option with -c-, like -wrap-, or -t, the output is again color.
PM'd the link to the file to Willus.
Please help. I'm at my wits end.  |
@Japinder--I couldn't get your PDF file. See my PM back to you.
It will help if you show exact options that you used for various cases. If you used
-mode tm (or selected "trim" from the Conversion Mode menu in the MS Windows GUI), this uses native output mode, and in native output mode, things like color, contrast, sharpness, and gamma factor cannot be adjusted, because the output file is identical to the source file except that it is cropped and scaled. So if you want to combine grayscale output with the trim mode, you need to 1. select "Trim" from the Conversion Mode menu, 2. be sure color output is unchecked, and 3. uncheck "Native PDF output." Unfortunately, as you have seen, the preview mode incorrectly shows the grayscale output (if you don't have color output checked) even when you have "Native PDF output" checked. This is a bug which I've added to my list to fix.
You may wish to experiment with the option which sets the white threshold:
-wt. You can use this to convert your background color to white assuming it is light enough (use
-wt+ to do this). For example,
-wp+ 128 will convert to white all colors that have an equivalent grayscale pixel shade (0-255) lighter than 128 (you can put this in the "Additional Options" box). Again, this feature only works if native output is turned off.
Finally, if you need higher resolution output (with native output mode turned off), bump up the "Document Resolution Factor" to a value higher than 1.0. E.g. 2.0 will double the output resolution.