V4.23 - Gamma correction only applied to first page

[MartynJ]

I am applying gamma correction to a multipage colour PDF before saving it as a monochrome (/tifc=4) TIFF file. The gamma correction is only being applied to the first page.

[Bhikkhu Pesala]

What do you expect? Why would the program assume that you want to make the same correction to each page?

[MartynJ]

I am running IrfanView from the command line in this instance. I obviously expected it to apply the correction to every page, otherwise I would not have reported it.

The help says that /gamma=X means "open image and apply the gamma correction value X", it makes no mention of it only changing the first page.

Is it possible to apply this correction to all pages using a single command line? If not would I need to split the PDF into multiple individual files, apply gamma correction to each, before creating a multipage tiff from the resultant corrected images?

Thanks for your help.

Martyn

[Skippybox]

Help says:

(some Misc. Advanced Batch options are not supported: overwrite, delete, subfolders, all pages)

Therefore, I would expect that other modifications to multipage files would be prohibited for most switches.

Is it possible to apply this correction to all pages using a single command line? If not would I need to split the PDF into multiple individual files, apply gamma correction to each, before creating a multipage tiff from the resultant corrected images?

You can do that, or convert to a multipage TIF first, then apply the gamma correction when converting to the final TIF in the GUI. If you want to do it via command line there is the /extract=(tif,ext) and /append=tiffile or /multitif=(tif,files) commands. I would put all the steps in a batch file for quick deployment. Here is a thread on how to do that with some important information. Here is a way to build a command when you don't the filenames:

@echo off
set Source=C:\TIF\
set Cmd="C:\i_view32.lnk" /multitif=(%Source%Test.tif
for /F "tokens=* delims=" %%a in ('dir /b %Source%') do call :Sub "%%a"
set Cmd=%Cmd%)
%Cmd%
pause
goto :eof

:Sub
set File=,%Source%%~1
set Cmd=%Cmd%%File%
goto :eof