reversing (inverting) black & white on a PDF

[wfriedwald]

if I have a basic PDF with black text on a white background, is there any way to invert that? (so what I want is white text on a black background). makes for easier reading at night.

 

[velocityg4]

Use Adobe Acrobat Reader. On a Mac the Preferences are likely under the Acrobat menu rather than the Edit menu. Don't have a Mac in front of me to check.

How to Invert the Colors in a PDF File in Adobe Acrobat Reader for Easier Nighttime Reading

The PDF format is meant to ensure the formatting of a document is preserved when viewed on different operating systems and devices.

www.howtogeek.com

If you're using Preview. The best I could figure is to invert all colors in Accessibility in System Preferences.

 

[wfriedwald]

thanks ... will try!

follow-up question: is there any way to generate a new PDF with the colors inverted permanently, I mean? Rather than a setting while reading. (Am reading on an Android device that doesn't have these options...)

thanks again!

w

 

[Slartibart]

Well there is the free Negative or if you use Preview, you can invert the screen colors for the entire system by pressing Command-Option-Control-8. Press the sequence again to restore the default color scheme.

if you permanently want to convert files install Imagemagick (via homebrew for example) and use:

convert -density 150 -channel RGB -negate "your-black-text-on-white-file.pdf" "inverted-new-file.pdf"

in the terminal. You can adjust the output dpi as well as the color model used in your “original” pdf if needed.

 

[wfriedwald]

oh boy ... HOMEBREW ... have never used that, I suspect it's a bit above my tech skills

I gotta admit, I thought this would be easier. oh well. Thanks for all the feedback!

 

[JustMartin]

Well there is the free Negative or if you use Preview, you can invert the screen colors for the entire system by pressing Command-Option-Control-8. Press the sequence again to restore the default color scheme.

if you permanently want to convert files install Imagemagick (via homebrew for example) and use:

convert -density 150 -channel RGB -negate "your-black-text-on-white-file.pdf" "inverted-new-file.pdf"

in the terminal. You can adjust the output dpi as well as the color model used in your “original” pdf if needed.

Thanks for the imagemagick tip. That works ok - but the command as given doesn't change the page colour, only the background of the letter. So, although you have lovely white on black lettering - the rest of the page is still white.

Negative is lovely, but I need a solution where the inverted PDF can go to a different device (not necessarily Apple)

 

[Slartibart]

Thanks for the imagemagick tip. That works ok - but the command as given doesn't change the page colour, only the background of the letter. So, although you have lovely white on black lettering - the rest of the page is still white.

Negative is lovely, but I need a solution where the inverted PDF can go to a different device (not necessarily Apple)

the imagemagick command inverts given objects… if there is no object in the background, well… 😀

The way I see it you have to export the PDF pages one by one as a pixelbased picture and then simply invert these Imagemagick to rescue:

convert -density 300 -background white -colorspace sRGB -alpha remove in.pdf -append out.png

Use the -negate parameter to invert the PNGs.

 

[JustMartin]

sorted myself out. I was creating a songbook with ms word. For stage use, it’s better to be white text on black background. Anyway - change text colour to white. From design menu change page colour to black. Then, there’s a preference for including background colour in the print. After that print to pdf works a treat 🙂