I take the original picture and use a web service to upscale it so that I have a larger canvas to work with.
Then the image is opened up in my app of choice Snapseed.
From there I alter the color curves which changes the information available from the black & white.
I start with the red channel changed the curve and them choose varying intensity for the different parts of the image (e.g. 100% where flesh, 75% with timber, 25% everywhere else). I repeat this for the green and blue channels.
After this I boost the saturation before adding back in a layer of B&W. To get to the final product I then use the selective tool to alter brightness, contrast or saturation until I am happy.
Thank you for asking!
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