Print gray text as "pure" black

Yes, I have lots of experience with software that can do exactly what you want.   Most of it is free as well. I will give the list that springs to mind.

1.  IrfanView is freely available from http://www.irfanview.com/ .  It is a graphics manipulation program - without editing facilities but lots of other useful tools.   Go to "Image" menu, and select "Decrease colour depth.   In the pop up box click on "2 colours (Black/White) (I BPP)"  

2.  If the grey is not very grey - in fact nearer white than black, then you  need to use a graphics editing tool to increase the contrast, or reduce the brightness.   There are numerous such tools around.   MS Office had one called MS Photo Editor which does it fine ("Image" menu - select "Balance").   IrfanView can't do this, but another free program XnView can - use "Image" menu, then select "Adjust - Brightness/Contrast/.......".   You will need to play with one of these tools to learn how to use it - blow the text up really large on screen and watch the effects of adjusting brightness and contrast until you get the hang of it.

After you have adjusted your brightness and contrast, you can generally use the same program (whichever you have selected) - to save the file if you use TIF file format, with "group 4 compression" - this is the smallest file size available for black and white files that I am aware of right now.

The trick to getting good results with this process is to adjust the brightness and contrast just so that the paper (background) stays white, while the text gets darker.   Note that it doesn't have to go completely black - just dark enough so that when you convert to black and white the conversion process picks up the text correctly - without introducing lots of black speckles into the white (background) paper.

With IrfanView and Xnview you can automate these processes if you have lots of very similar files to work on.    They both have batch processing features that allow you to set the process you want - including adjusting brightness and contrast and then converting to black and white.  Naturally this only works if your source files are similar in the "greyness" of the text" - and the whiteness of the background.

I mention just some of the software I have used.  There will be other software.   Most graphics programs can do the job - albeit sometimes rather clumsily.   Photoshop and its derivatives seem to be some of the exceptions - they are strictly for colour or greyscale photos and don't recognise black and white images as existing!  I have had various bits of software supplied with scanners over the years which have been useful - you may have them too lying about - not yet tried.   MS Document Imaging - which came free with MS Office was a very useful program at one time - most of the features have been stripped out in the later incarnations of Office (2003 etc) - but that was also a "freebie" (once you pay for Office) that few seem to discover.

If you want to know how I have discovered all this - then it comes from working on old WWII documents and learning how to scan them to restore them to pure black and white image files for easy distribution and storage.   A typical WWII document is on brown (now) paper, with very faded ink that is just discernible - in other words reading the original is not easy.   Good quality black and white pages can be recovered but it takes patience and attention to detail.


Richard