Trying to understand Rorshack OctaveRawTools

[ttbek]

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You can select from many demosaicing methods in RT. What if you try method 'None' to your synthetic DNG?

Thanks for your response. Sorry for not making myself clear. I included the crop from rawtherapee for comparison to the red channel enlarged by summing the DPRAW data.

I do not remember which demosaic algorithm I used in rawtherapee this time.

I think you did not get my point.

RT's demosaicing method 'None' means no demosaicing. Jack suggested remosaicing your dng. I thought what happens if you did open your dng in RT without demosaicing because it already was demosaiced.

Thanks again. I used libraw instead of ratherapee to separate the color channels into individual files. I then modified the individual files by upscaling and addition.

I do not know how to create a bayer array from the individual channels and write it into a format that rawtherapee can process. I do not know how to create a dng with 4 times as many pixels as the original. I am old and I have forgotten much and I might be missing something obvious.

You asked in your OP "Do any know how I might combine the individual channels after scaling so they might be demosaiced by rawtherapee?"

And "Here is a crop done in ratherapee after normal demosaic:"

My understanding of it is that the crop is coming from the unmodified file, he has:

1) Original raw -> split channels -> scaled -> DO SOMETHING to recombine the files -> RawTherapee

He needs to know what to do at the DO SOMETHING step, he wants to compare with the other one he is showing:

2) Original raw -> RawTherapee with normal demosaicing

I think that's the situation, so if he opens the original raw without demosaicing, then he's skipped the steps he wants to compare, and to open the ones he did the steps on, he needs to do something to combine them into a dng or something first, at which point he can open without demosaicing as you suggest, so he needn't undemosaicing it per se if he does demosaicing while combining them somehow.

My idea was opening it without demosaicing. I'm asking you to open your dng in RT, going to the raw tab, selecting the demosaicing method "None" ,looking at the preview.

At first glance, the red channel file I posted seems to me to have greater resolution than the crop from the original that I created in rawtherapee because rawtherapee had processed one of the 2 DPRAW images at the original resolution.

This goes over my skills.

Thanks again