Displaying 1x1 fits images in ximtool
Jason Quinn wrote on Jun 01, 2009
I tried displaying a 1x1 (that is, a one pixel) fits file and I learned several things. First, IRAF cannot display such an image using the display command. You get a
ERROR: Insufficient sample pixels found
error. I assume this is related to some zscale calculation but rather than failing perhaps the code should try to work around whatever the problem is.
Secondly, loading up a 1x1 fits image from the command line, which works, seems to expose several bugs in ximtool (I'm running the latest version). For one, the pixel value is never reported properly. I am using an image with just the value 0.1185 which ximtool is reporting as 2.76e-07. I have noticed that the value for pixels even in normal images sometimes is not the actual pixel value of the pixel beneath the mouse cursor (frequently the value reported comes from a neighboring pixel). I suspect that there may be "one-off" style errors presently in ximtool. There are also other strange things. If you open the control panel and go to the coords tab and display the "WCS/Pix" pane, you can see that the "scaled value" changes when the mouse is hovered over the lone pixel but the main window's value never changes. In general, 1x1 images may be extremely useful to debug ximtool.
My original 1x1 image was automatically generated as the kernel in a pipeline; so while a little corny they is some reason to support them.
Jason
ERROR: Insufficient sample pixels found
error. I assume this is related to some zscale calculation but rather than failing perhaps the code should try to work around whatever the problem is.
Secondly, loading up a 1x1 fits image from the command line, which works, seems to expose several bugs in ximtool (I'm running the latest version). For one, the pixel value is never reported properly. I am using an image with just the value 0.1185 which ximtool is reporting as 2.76e-07. I have noticed that the value for pixels even in normal images sometimes is not the actual pixel value of the pixel beneath the mouse cursor (frequently the value reported comes from a neighboring pixel). I suspect that there may be "one-off" style errors presently in ximtool. There are also other strange things. If you open the control panel and go to the coords tab and display the "WCS/Pix" pane, you can see that the "scaled value" changes when the mouse is hovered over the lone pixel but the main window's value never changes. In general, 1x1 images may be extremely useful to debug ximtool.
My original 1x1 image was automatically generated as the kernel in a pipeline; so while a little corny they is some reason to support them.
Jason
Mike Fitzpatrick wrote on Jun 01, 2009
Hi Jason,
This is actually an old bug that was in the original XImtool, it is actually also a new bug in that the ISM module that provides the real WCS and pixel values iis also affected. I've added your report to the list of things to be fixed the next time I work on this, at the moment I'm swamped with other things.
Cheers,
-Mike
This is actually an old bug that was in the original XImtool, it is actually also a new bug in that the ISM module that provides the real WCS and pixel values iis also affected. I've added your report to the list of things to be fixed the next time I work on this, at the moment I'm swamped with other things.
Cheers,
-Mike
Last post on Jun 01, 2009