In the days of film we used to experiment with the chemical process to try and make our images different from others. One of those was the bleach bypass process in which you skipped the bleach stage leaving silver on the emulsion. This would give the impression of a black and white overlay on the final image.
This can be achieved or simulated in photoshop and this is just one example.
Process normally so that you have the image colour corrected and the curves and levels are correct.
Duplicate layer twice. We want to create a mono layer to overlay the image as in leaving silver on the emulsion. Now switch the blending layer on the top layer to screen.
The image will lighten substantially. Now with the top layer selected press [Ctrl] + [E]. Now click on adjustment layers and black and white. Use the sliders to produce a high contrast image.
We only want the mono effect to effect the present top layer. Hold down [alt] and hover the cursor between the adjustment layer and image layer and you will see the cursor change. Left click when you see this. Change this layer to soft light.
Make another copy of the background layer and move it to the top. Click Filter.Other.High Pass and select a value where you get something that looks similar to an embossed print. Use the Layer Blending Mode to set it as Overlay.
You now have the basics to work with, fine tweaks such as contrast, colour saturation can now be made and you have your bleach bypass effect.
Does anyone else play like this?
This is the original image for comparison