by Chris Peterson » Sun Feb 03, 2013 4:21 pm
BDanielMayfield wrote:The numbers are pixel coordinates, with 1,1 being on the top left corner of the image.
This convention is a technical curiosity, a consequence of the fact that the first television displays constructed their images by sweeping a raster from the upper left corner of the screen. Since the first digital display devices used television technology for their displays, the memory buffers that mapped to the image treated the upper left as the origin. Otherwise, we'd probably use the more reasonable first quadrant, with the bottom left being the origin. So now we're left with needing to reflect all the standard equations for rotation and translation when doing image processing. (BTW, the origin pixel in the upper left is normally (0,0), not (1,1) - does your image processing software actually show it as the latter? That would be odd.)
There you will find a very dark object that at some magnifications looks rather unnatural. (To be clear, I don’t actually believe it to be some sort of artifact, but … )
- apod_detail.jpg (9.42 KiB) Viewed 4224 times
Ann might well be correct that this is a region hollowed out by stellar winds. I'm more inclined to go with your guess, however, that it's a dust globule of some sort. It looks to me like a star is being occluded, which wouldn't be the case if this was a cavity. If it's a dust globule, it could be coincidentally in front of a star, although it seems more likely it would be associated with that star in some way- part of a protostellar structure, perhaps.
[quote="BDanielMayfield"]The numbers are pixel coordinates, with 1,1 being on the top left corner of the image.[/quote]
This convention is a technical curiosity, a consequence of the fact that the first television displays constructed their images by sweeping a raster from the upper left corner of the screen. Since the first digital display devices used television technology for their displays, the memory buffers that mapped to the image treated the upper left as the origin. Otherwise, we'd probably use the more reasonable first quadrant, with the bottom left being the origin. So now we're left with needing to reflect all the standard equations for rotation and translation when doing image processing. (BTW, the origin pixel in the upper left is normally (0,0), not (1,1) - does your image processing software actually show it as the latter? That would be odd.)
[quote]There you will find a very dark object that at some magnifications looks rather unnatural. (To be clear, I don’t actually believe it to be some sort of artifact, but … )[/quote]
[float=left][attachment=0]apod_detail.jpg[/attachment][/float]Ann might well be correct that this is a region hollowed out by stellar winds. I'm more inclined to go with your guess, however, that it's a dust globule of some sort. It looks to me like a star is being occluded, which wouldn't be the case if this was a cavity. If it's a dust globule, it could be coincidentally in front of a star, although it seems more likely it would be associated with that star in some way- part of a protostellar structure, perhaps.