How can I print out a PDF substituting pixels for blue pixels?

Question

I have no more black ink in my Canon MP560 printer.

All other colors print fine.

I need to print out an online train ticket.

When I print it out, I can't see any of the page that is in black (most of it, all the text).

I already printed it as a PDF so I can print it out later if I get some black ink in time.

But can anyone think of a creative way to tell the printer / printer driver / PDF software (Foxit) that it should replace all black pixels with e.g. very dark blue pixels so that I can at least print it out so that the barcode on the page can be scanned?

Answer 1

Install Ghostscript (first) and then ImageMagick, and then you can use the following command:

magick convert -density 300 input.pdf -fill blue -opaque black output.pdf

This will convert all the black in input.pdf with blue in output.pdf.

[Thanks to Nick's comment below for the part about ghostscript.]

Note added later: If you have a newer version of imagemagick that doesn't have a convert binary, use magick convert instead of simply convert.

Answer 2

There's a free online tool that's built for this very purpose:

https://supertool.org/automatically-add-color-to-pdfs-to-print-without-black-ink/

It took a little while to load and process, but it made it possible to print a return shipping label without black ink.

Answer 3

An addendum to frabjous' answer requiring Ghostscript and ImageMagick are installed, including the updates according to Alexander Taubenkorb's comment.

This still didn't work because I had the problem that the 'gray' of my image was not pure gray. To overcome this I switch the colorspace “back and forth” to ensure there is a clean definition of ‘gray’ to be converted to blue in that final command.

convert -density 300 input.pdf -colorspace RGB -colorspace Gray tmp1.pdf

convert -density 300 tmp1.pdf -colorspace Gray -colorspace RGB tmp2.pdf

convert -density 300 tmp2.pdf +level-colors blue,white output.pdf

Answer 4

Maybe you can set an option in the printer driver to print black as composite from yellow, magenta and cyan.

Answer 5

For Canon MG3600 I could find an option to select only the "Color Cartridge". From the print dialog, select Properties > Maintenance > Ink Cartridge Settings > Color Only.

I think it make color composite to give black, as the result was indeed black although I my black cartridge is empty.

Answer 6

I followed frabjous's answer above and changed the command like this.

magick.exe -density 300 "input.pdf" -fuzz 50% -fill red -opaque black "output.pdf"

Worked perfectly, worked in text as well as images in the pdf too.

Answer 7

You can change the colour of font settings in Adobe Acrobat. After doing that it still tries to print black on the font but fear not. If you manage to change the font colour, change the advanced setting in (HP at least) to print as picture and it will print in dark blue.

I discovered this by chance, hopefully it helps someone else!

Answer 8

For the record: just remove the empty black cartridge and print document as image (print -> advanced tab -> tick "print as image") - your printer will do its best to reproduce blacks using only the color cartridge. It will not be perfect, but for me it managed to produce a rather convincing dark blueish-grayish tone.

*I used Acrobat DC with a HP Deskjet 2620

Answer 9

In a HP Deskjet and probably most printers, I just change the setting to print as if its an image or photograph. Works perfectly as it prints the black from the combo in the colour cartridge.

Answer 10

EDIT: after posting this answer, I realized the print still comes out in black. It's only the screen view that changes (at least in my PDF reader). But it still provides a solution because you can then print a screenshot. I pasted my screenshot into Word and dragged the corner of the image to make it a bit bigger before printing it.

Some PDF readers let you do it as an Accessibility setting under Preferences.

For example, Foxit Reader does it here:

I read somewhere that Adobe reader has a similar setting.

Answer 11

[Mac] Open your PDF from within Colorsync Utility. At the bottom of preview window, there's a dropdown box. Select the "blue tone" filter. Save as a new PDF. Works great!

Answer 12

Try this

convert -density 300 vinted-pdf-1.pdf -fill blue +opaque white,gray image.pdf

Answer 13

I don't know about the print drivers or PDF part, but I would save the PDF as a graphic and use an editor (like gimp or something) to select all of a color (black) and change it to blue.

Answer 14

A brute force method, if you only need the bar-code, is to print screen and open the picture in your favorite photo editing program to manually shift the colors.