Details
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Type:
Story
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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:
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Story Points:2
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Epic Link:
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Sprint:SUIT Sprint 2018-06
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Team:Science User Interface
Description
When using lsst.afw.display.dot with the Firefly backend, positions appear at a half-pixel offset from where they should; LSST convention is to label the center of the lower-left pixel (0, 0).
I also see the same half-pixel offset in the mouse pixel coordinates displayed in the upper right corner of the Firefly GUI, so I'm guessing this is just because Firefly (presumably) using a coordinate convention in which integers are pixel boundaries rather than pixel centers. If it's possible to address that, it'd be very nice to also include the "xy0" offset our image objects carry as well (note that dot already takes care of this offset correctly, presumably by removing it in Python before passing the position to Firefly).
I'd really appreciate a quick fix so I don't have to work around this in the tutorial notebooks for LSST@Europe3 next week. If the only short-term options is a workaround for dot in the display_firefly Python code, I can do that much myself; please let me know if I should.
Attachments
Issue Links
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DM-14681 Develop tutorial notebook for LSST@Europe3
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Jim Bosch do I understand that in ds9, the LSST xy0 convention is implemented in WCS a? After reading the HCS-I coadd into ds9, the lower-left-hand pixel is 1, 1 in Image; 15901, 15901 in Physical; and 15900, 15900 in WCS a. It's the WCS a that Firefly needs to handle?