This should be possible with PDF-Tools.Graphics Downsampling options (Linear, Bilinear, Bicubic) also Colour -> Grayscale -> Mono options
Also I found the following quote from here: viewtopic.php?t=3804&p=16983#p16983
Now, my question is: How can I convert images from colour to mono?John - Tracker Supp wrote:PDF-Tools will allow you to reduce image files by downsampling and conversion of image fiiles from full colour to grayscale/mono
I would expect that I con do this with "Save as Optimized" (PDF-XChange Editor) respectively "Optimize PDF" (PDF-Tools). But I cannot found this option.
I found this option in the editor only for a single image: open the content pane, expand the content of a page, open context menu with right click on an image, choose option "Recompress image..."
My challenge is to change 600 images in my document and I am not willing to compress all 600 images one by one.
Therefore I have selectet all images and tried to compress all at once. But when I select more than one image the option "Recompress image..." is no longer displayed.
What can I do?