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Topics - alexxw24

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Hi everyone,

e.g. Juan mentioning CFA DrizzleIntegration as the recommended way for integrating DSLR/OSC data some time ago (see underneath).
I'm usually working with a mono-CCD but have some DSLR widefields from earlier this year to process ahead of me.

I want to understand the background, why CFA Drizzle is supposed to be better / recommended, well dithered and larger number of sub frames assumed.

The positive effect on undersamples subs I am aware off but what makes it with the bayer matrix, better color interpolation?

Thanks for your thoughts,
Alex


Quote
I am under the impression that AHD is superior to VNG.

Why? Yes, we can implement more CFA interpolation algorithms in the Debayer tool. However, this is not a priority task for the following reason: In current versions of PixInsight, CFA interpolation with the Debayer tool is intended exclusively for generation of temporary working images, required as input for StarAlignment. The only recommended way to generate integrated color images from CFA raw data, be it data acquired with digital cameras or single-shot CCD cameras, is DrizzleIntegration (i.e., CFA drizzle, AKA Bayer drizzle). The only exception may be if you have just a marginal number of raw frames, where drizzle may not be applicable.
....

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General / calculating real bit depth / quantization
« on: 2018 September 25 11:45:03 »
Dear members,

any idea how the real bit depth of a sub frame could be calculated using e.g. pixel math or a self-written script?

In detail, I want to determinate the absolute number of different values used in a mono or RGB subframe (per channel)
1) as strongly believe to not always have to use 32bit floating for saving an image
2) as we have a nice dicussion in our local astro community regarding gain settings.

For example a 16bit image can store 65535 values but there are only 30587 in the subframe.
In the HDR composition process  for example an initial quantization is given out at the console, what's the calculation behind?

Thanks in advance and best regards,
Alex

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