Details
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Type:
Bug
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Status: Done
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Resolution: Done
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Fix Version/s: None
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Component/s: Firefly
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Labels:None
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Story Points:2
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Sprint:SUIT Sprint 2016-9
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Team:Science User Interface
Description
The rotation of a z-scale log stretched or north-up image operation fails and changes the stretch. The image becomes black/white.
That doesn't happen with linear stretch btw.
It looks like a server -side problem.
Step to reproduce:
Either by searching from Spitzer GOALS images or just uploading the attached FITS file, then stretch on 'z-scale log', then rotate (45deg). The stretch changes. Same for north-up operation.
Attachments
Activity
My previous tests showed that the rotation bug was fixed so that the image size won't be too large for the server to handle, the zscale might still have some problem. See the test case:
When using the attached fits file, select Zscale Linear Stretch, rotate the image by 5 deg for several times, the color of the image changes after each rotation.
I have talked with Lijun about it. I will continue to debug the zscale code.
Yi Mei [X] (Inactive)
added a comment - My previous tests showed that the rotation bug was fixed so that the image size won't be too large for the server to handle, the zscale might still have some problem. See the test case:
When using the attached fits file, select Zscale Linear Stretch, rotate the image by 5 deg for several times, the color of the image changes after each rotation.
I have talked with Lijun about it. I will continue to debug the zscale code.
Checked Zscale.java and confirmed that the amount of NaNs added by each rotation do have effect on ZScale, low and high values. That is why the color of image changes after rotations when ZScale is used.
DS9 is doing different thing: Rotation doesn't change the fits data and only the client side handles the rotated image.
No further debugging is needed at this point, per Trey.
Yi Mei [X] (Inactive)
added a comment - Checked Zscale.java and confirmed that the amount of NaNs added by each rotation do have effect on ZScale, low and high values. That is why the color of image changes after rotations when ZScale is used.
DS9 is doing different thing: Rotation doesn't change the fits data and only the client side handles the rotated image.
No further debugging is needed at this point, per Trey.
Trey approved merge of this pull request.
Merged to dev.
To verify if the changes in Geom could introduce problems., I tested how the histogram and stretch handled NaN. Here is what I found: