Perhaps I should open a new thread? let me know
I want to use Retinex to dehaze a photo.
You can find my example here. It is a D80 NEF file. As PP3, I use standard.
My aim is not to find the optimal result but only how to dehaze with Retinex, getting an acceptable starting point.
My first step is so to enable Retinex : terrible result with a pink sky.
second step : I try to display the transmission map. This map should be a kind of representation of atmosphere thickness as the mask provided in same link above (not in same dimension)
To display it in Retinex, I click on “process” and I have the choice between two transmission masks. The two of them seem weird.
- What are they representing?
- Why as I just want to display an existing mask, the processing pipeline is replayed?
- why the transmission mask are colorful?
- why there are halos?
In order to obtain the desired dehaze effect, the transmission mask can be modified with a luminance curve ( S shape for example) to increase or decrease foreground and background.
- where is the luminance curve which modulates the transmission mask?
So Ideally the only parameter needed is a luminance curve or cursors to modulate the density of the transmission mask.
I surely missed something even after reading the french rawpedia.
Your help and explanation will be welcome (particularly @jdc)
Please stick on the subject of dehazing.
I am not asking for processing advice (the photo is not worth this kind of effort)
Please answer in I want to dehaze…