How can I convert a color PDF image to B/W? 2

[kenford]

I need to use some images in a document for black and white printing (with one spot color) that I have only in PDF format. As far as I can find, neither Photoshop Elements nor Indesign allow me to convert a color image in PDF format to black and white. Any suggestions appreciated.

 

[apepp]

...never used PS elements so not sure if it can open pdf files or if you can choose image > mode > greyscale?

...you would then need to place the resulting grey image on top of a placed pdf in indesign and then re-export to pdf...

...with acrobat you can save out to a grey postscript via file > save as, this may depend on what acrobat version you have, then distill the postscript file to pdf, then use indesing to combine and re-export to pdf...

...with acrobat pro you can also select an image using the touch up object tool and right click for edit image, this can sometimes open the image in photoshop and you can then convert to grey space, save and the image gets put back into the pdf file. I say sometimes because depending on where this pdf came from that isn't always possible...

...acrobat pro can also convert color to black and white under advanced menu > print production for a whole document, but depending on document structure it can be a bit hit and miss using the gamma profiles or the dot gain destination profiles. In any case, you need the proper creative suite for this. I've had more success by creating a black and white ink profile from a cmyk profile via photoshop, and using that as the black and white destination space. This is achieved by loading your cmyk working space profile into the grey space of photoshop color settings.

...another way is to place pdf in indesign, print to postscript as grey composite, either open postcript file in photoshop, or distill it to a raw pdf so resolution isn't affected, then use indesign to combine to a new pdf...

Andrew

 

[apepp]

...the other method is by way of enfocus pitstop, a plugin for acrobat pro, that makes pdf edits and conversions, but this costs money...

Andrew

 

[apepp]

...you can potentially use illustrator to convert to greyscale too...

Andrew

 

[kenford]

Thanks, I'll work with this. (PS Elements does allow me to change the mode for an image to greyscale, but I can't open a pdf file in PS Elements.)

 

[eugenetyson]

In InDesign select the colour pdf(s) you want converted.

Then change their transparency to 99.9%.

This is enough to push them through the transparency flattner.

Now instead of Export to PDF, PRINT to Acrobat PDF

Change the Colour Output to Composite Gray, make sure that this is the last thing you do before you press print. (sometimes it reverts to the CMYK or RGB if you click other places in the dialog box).

That's how you get indesign to "convert" to grayscale!