Hey all,

I would like to do a custom monochrome conversion of any color image using a script. All colors except those in a narrow range are to be converted to white, and the colors within said narrow range are to be converted to black.

I've attached a sample picture to this post; the objective is to basically get a black dot in a white background (the black dot coming from the red dot).

Any advice on how to go about this?

Also, which is the best file format for quick image scanning/manipulations/conversions and maintenance of sharp edges? PNG?

Cheers.

Attached Thumbnails

 

For image manipulations you should use a format without compression, like BMP. Commandline tools for image editing and conversion are avilable, for example the ImageMagick tools, which should be available for amy distro. I am not experienced with those, but it should be possible to use them for your purpose.
I hope that helps a bit.

And what would those in the "narrow range" be converted to?

I'd like to know if there's something comprehensive too. I'm familiar with Photoshop and GIMP and both allow the bucket fill to "fill by color" however they both tend to find boundaries in shading, lines, or other things where the stop. Like I took a picture of Mt. Everest and tried to convert it using that technique and ... you'd be amazed how many shades of white ice/snow there are. Or they are interrupted by lines of some type. Hence you click and it fills some, but nowhere near enough.

Next, I am familiar with algorithms, unfortunately proprietary stuff where they scan line by line and filter, plus convert. So via a program, I'd follow those same procedures, which would be to load a line of pixels in an array, or rather load the whole picture if needed, then process the whole thing like a serial buffer, just [0][0] to [n][m] and convert based on a choice like > 50% = black, else = white.

Hey all,

I found out how to do it.

http://www.fmwconcepts.com/imagemagi...lors/index.php

In bash, type:
locatecolors -b "rgb(245,0,0)" -e "rgb(255,0,0)" -m and nature_dot.png out.png

The script doesn't work with jpgs, so you have to convert it first.
convert nature_dot.jpg nature_dot.png

Cheers.