Contrast Blending: Step by step manually
Contrast blending main
This is a description of what happens in
the contrast blending actions step by step. The contrast blending technique
might be used with programs other than photoshop, provided they support
masked layers. Many thanks to Jacek Zagaja for the test images. The crop
I use here for demo only is from img_2339.jpg found in lamp.zip
(605 kB). Please download for own experiments.
After having processed all layers, adjust
layer opacity in order to get a natural appearance as described in the
Open darkest image
Open lighter images as layers proceeding from
darker above the background to the lightest on top.
create a mask for layer 1 and above (background
copy the layer content to the mask, desaturate
if necessary. Mask should look like this:
Use a smart blur filter on the mask with radius:
8, Threshold: 50, Quality: High, Mode: Normal. These are photoshop specific
values. They might be different in other programs. However, the mask should
look like this afterwards:
As you can see, small details are blurred
as well as low contrast edges. Hard contrast edges are untouched.
If the pixel steps in the edges bother you,
you can perform a gaussian blur on the mask with radius between 0.5 and
1.0. Please note that the result might be sharpened a bit by this step.
Mask might look like this afterwards:
Apply a curves adjustment to the mask. Curve
points should be: point 0: 0, 255 point 1: 128, 236 point 2: 216, 128 point
3: 255, 0
The curves dialog looks like this in photoshop:
The mask after curve applied:
set layer opacity to 50%.
proceed with all other layers.
© Erik Krause 2004