comp.lang.idl-pvwave archive: archive

Home » Public Forums » archive » IDL ROI Objects

Show: Today's Messages :: Show Polls :: Message Navigator
E-mail to friend

Re: IDL ROI Objects [message #90104 is a reply to message #90101]

Tue, 27 January 2015 15:10

Fabzi
Messages: 305
Registered: July 2010

Senior Member

On 27.01.2015 19:53, David Fanning wrote:
> The ROI code has a left-bottom bias.

Disclaimer: I did not read the original poster code, because it is not
close enough to a "minimal working example" for my taste, but IDLanROI
has a pixel centered convention, and a "pixel area convention" (a pixel
touched is a masked pixel):

IDL> x = [0., 0., 0., 0., 0.]
IDL> y = x
IDL> roi = OBJ_NEW('IDLanROI', x, y)
IDL> print, roi->ComputeMask(DIMENSIONS=[3,3])
255 0 0
0 0 0
0 0 0
IDL> roi = OBJ_NEW('IDLanROI', x-0.49, y-0.49)
IDL> print, roi->ComputeMask(DIMENSIONS=[3,3])
255 0 0
0 0 0
0 0 0
IDL> roi = OBJ_NEW('IDLanROI', x+0.49, y+0.49)
IDL> print, roi->ComputeMask(DIMENSIONS=[3,3])
255 0 0
0 0 0
0 0 0
IDL> roi = OBJ_NEW('IDLanROI', x+0.51, y+0.51)
IDL> print, roi->ComputeMask(DIMENSIONS=[3,3])
0 0 0
0 255 0
0 0 0

If you discovered a bug, can you try to reproduce it in a smaller
example? Since you seem to mix pixel and polygon a little bit, could
your problem be related to some floating point precision issues?

Just my 2c, maybe I missed the point.

Fabien

Report message to a moderator

[Message index]

		IDL ROI Objects By: David B on Tue, 27 January 2015 09:28
		Re: IDL ROI Objects By: David Fanning on Tue, 27 January 2015 10:53
		Re: IDL ROI Objects By: David Fanning on Tue, 27 January 2015 11:00
		Re: IDL ROI Objects By: Fabzi on Tue, 27 January 2015 15:10
		Re: IDL ROI Objects By: David B on Wed, 28 January 2015 02:00
		Re: IDL ROI Objects By: David B on Wed, 28 January 2015 02:06
		Re: IDL ROI Objects By: David Fanning on Wed, 28 January 2015 06:12
		Re: IDL ROI Objects By: David Fanning on Wed, 28 January 2015 06:19
		Re: IDL ROI Objects By: David Fanning on Wed, 28 January 2015 09:17
		Re: IDL ROI Objects By: Fabzi on Wed, 28 January 2015 09:49
		Re: IDL ROI Objects By: David Fanning on Wed, 28 January 2015 10:17
		Re: IDL ROI Objects By: Fabzi on Wed, 28 January 2015 10:30
		Re: IDL ROI Objects By: David Fanning on Wed, 28 January 2015 10:42
		Re: IDL ROI Objects By: Fabzi on Wed, 28 January 2015 10:56
		Re: IDL ROI Objects By: David Fanning on Wed, 28 January 2015 11:20
		Re: IDL ROI Objects By: Fabzi on Wed, 28 January 2015 11:24
		Re: IDL ROI Objects By: David Fanning on Wed, 28 January 2015 11:38
		Re: IDL ROI Objects By: David B on Thu, 29 January 2015 02:05
		Re: IDL ROI Objects By: Fabzi on Thu, 29 January 2015 02:50

Previous Topic:	Krig2d from point to image
Next Topic:	Re: Why did IDL just start crashing

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

] [

]

Current Time: Wed Oct 08 16:14:31 PDT 2025

Total time taken to generate the page: 0.00392 seconds