Histogram

[silver]

A large histogram as separate screen / window would be useful. The histogram in the color module is too small.

[Rkonrad]

I would agree. A histogram would be useful especially if one is continuing to process after tracking is finish. Ivo, I believe you have said that blacks cannot be clipped while tracking is on.

Cheers Richard

[admin]

Hi,

What use case would you have for the histogram specifically, within StarTools?
Thanks!

[Rkonrad]

Is it possible to clip the black point once out of tracking? I thought you mentioned it was possible (though not once tracking is on). I remember I have done so a few times in the past but can't remember the specifics.

Richard

[admin]

Honestly, you'd really have to go out of your way. One way to possibly clip your blacks is using AutoDev; use an RoI and set Outside RoI Influence to 0%. You could also do something weird in the Layer module, or use some extreme parameters for Dark Anomaly Filter and Aggressiveness in Wipe or Contrast.

Even then, not all clipping is created equal. If your data is noisy, you got some dead pixels or you got dust on your sensor that your flats didn't catch, then something like Wipe will possibly clip your data in those areas; it's more important to subtract the background model and free up dynamic range for the interesting signal than to retain dynamic range to describe the anomalies or 'negative' noise spikes.

[Rkonrad]

Thanks Ivo,

That's very clear. I'm not sure what I did in the past to clip the blacks. It could have been a noisy image as you said. Thanks.

Richard

[admin]

Do let me know if you see something out of the ordinary, or if you can think of a situation within StarTools where a detailed histogram is needed.

[jimmy101]

Ivo, I think it is useful. For example I know when stretching data that if the histogram peak is about 25% along it results in a manageable background so it would be nice to know. I am assuming that "home in" is doing the same but sometimes it's nice to know via the histogram if it's worth pushing the data more. Also when creating seperate channels for say narrowband Lum it's nice to be able to see where each channels histogram peak is located.

[admin]

1.5 has been released. A histogram can now be found in the Develop module.
Cheers!

[jlh]

Hi Ivo,

Would it be possible to have the histogram shown during the whole Startools process; maybe in a separate floating window that could be opened when desired? I think having that histogram would be a big help to me in trying to understand the effect of the modules, which to use and when to use them for particular images, as well as the effect of adjusting parameters in those modules.

Thanks,
Jeff