Sub region for histogram

Image processing, astrometry, photometry, etc.
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Jfisher6626
Posts: 11
Joined: 13 Jun 2024, 23:13
Location: Minnesota

Sub region for histogram

Post by Jfisher6626 » 18 Jun 2024, 18:47

Still learning the basics of AA. The profile tool is very handy for looking at spectra profiles but I’m looking for
A more efficient way. Is there a way just to draw out a subregion and get a histogram on that? I tried drawing rectangles but
It doesn’t change the xy coordinates in free profile. There must be a way,right? Thanks john

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bill
Posts: 10
Joined: 15 Jan 2019, 02:35

Re: Sub region for histogram

Post by bill » 18 Jun 2024, 23:56

Hi John,

You could make a duplicate image, F2
Then select a rectangle of the region of interest freehand or CTRL+R and select using the dialog box, and choose Crop from the image menu.
With the cropped image, select histogram to show the data.

Regards,
Bill
Last edited by bill on 19 Jun 2024, 02:57, edited 1 time in total.

Jfisher6626
Posts: 11
Joined: 13 Jun 2024, 23:13
Location: Minnesota

Re: Sub region for histogram

Post by Jfisher6626 » 19 Jun 2024, 01:39

Hmmm, I’ll try it,thanks. John

fabdev
Posts: 495
Joined: 03 Dec 2018, 21:43

Re: Sub region for histogram

Post by fabdev » 19 Jun 2024, 02:08

Hi, once a Profile is placed on the image, it can be moved and updated in real time: from the Profile Window, click the "Graph" icon (Change profile), then in the next dialog window click the "Center Y" box and use the mouse wheel to slide up/down the profile (assuming that the spectrum is horizontal).
For a better S/N of a spectrum, consider the command "Binning" for spectrums: draw a Rectangle over the spectrum, then menu Image / Binning / Y Average.

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