PDF conversion from color to grayscale

[egitre]

I have a collection of OCRed PDFs. The JPEG images in the PDFs are currently in color. I know that I can import the images from PDFs into grayscale upon opening, but the various output options only appear to save the current image in the browser window into grayscale. Is there a way to transform all images in a PDF from color to grayscale. Batch conversation of multiple PDFs would be amazing, since I have a number of them currently saved in color. Also, I want to preserve annotations, OCRed text, etc., in the saved PDF output file.

[forum_adm]

Hi,

the function Resample PDF in Convert&Modify can convert to B&W images with keeping all other PDF content.

Thorsten

Screenshot 2019-07-18 08.00.14.jpg (112.76 KiB) Viewed 3795 times

[egitre]

Thank you for responding. I got to the screen shown in your screenshot. After selecting Start selected Function, followed by Convert to B&W (leaving 128 as the threshold value), Graphic Converter indeed created a new output file. Yet all the images are still in color.

[egitre]

My reply seems not to have been saved. In any event, I tried this feature and the resulting PDF GraphicConverter produced was still (also) in color. Any suggestions?