How to maximize contrast in a desaturated image?

Question

I have a large number of full color product images that need to be recognizable when printed on a black and white office printer. For example, an image may contain two different hues that desaturate to the same value; I want to ensure that they remain distinguishable. The result doesn't need to accurately represent the relative brightness of the colors in the original image. It just needs to have enough contrast that warehouse pickers can recognize the item. Hard mode: I want to do this automatically.

I'm a software guy, so not even sure I'm using the right words to describe what I'm trying to do.

Answer 1

Software like adobe photoshop and adobe lightroom can transform to black and white (which is different than desaturation) in an automatic manner, that will ensure more contrast between the colors present in the image.

For example, in photoshop:

For maximum contrast, once you have the resulting grayscale image, you can apply automatic levels adjustment so that it reaches pure whites and pure blacks, scaling everything in between.

For example, in photoshop (pressing "Auto"):

Both software can modify images in batch.