Simulating Analog Black & White
There are millions of black & white photo plugins available. Some simple, some complex. When I recently got back a batch of real developed black & white film, I tried to investigate my scans to see how to emulate the effect (and possibly how to automate it).
The simplest approach I’ve been able to come up with involves blurring and decreasing contrast (with output levels). It can be automated with ImageMagick like so:
# convert -gaussian-blur 1x1 -filter triangle -resize 3000x2000 -level \!15%,\!95%,1.0 -colorspace gray -gaussian-blur 5x1 input.jpg output.jpg
Please note that doesn’t involve noise simulation yet, which seems to be hard to do with ImageMagick (tips are welcome). Please do note that I’m resampling to 6MPixels for convenience, you can use any resolution assuming you roughly scale along the 5 pixel Gaussian blur.