10-21-2019 05:35 AM - edited 10-21-2019 05:46 AM
I have loaded the western_accuracy.blk that comes as sample data for ERDAS in Stereo Analyst and am digitising buildings. Am using ErdasImagine 2018, red blue glasses.
(a) adjust x-parallax in left hand window (marked as 1 in image) with the keyboard using Shift+X and the mouse.
(b) adjust the floating cursor using the mousewheel in bottom left and right windows (2 and 3 - so they are resting on the same point)
(c) The x parallax in left hand large pane (1) does not change when using mousewheel in Step (b). The blue/red cursors separate in pane (1) when I use the mousewheel. In other photogrammetry software in the past adjusting cursors height with mousewheel would also give you finer control over adjusting x parallax than in Shift +X (step a). Ive looked for some toggle that I am missing but cannot find it. At the moment i can only digitise adjusting x parallax with Shift+X but the floating cursor is relatively useless and you lose that fine control.
Any suggestions as to what I am doing wrong?
10-21-2019 12:36 PM
In order to adjust X parallax in SAfI, in stereo window hold down the 'x' key, press left mouse button, and move the mouse horizontally.
And to adjust Y parallax hold down the 'y' key, and move the mouse vertically.
When you take care of local X and Y parallax and the elevation value is correct you shouldn’t see the blue/red cursors separate.
And if you are zoomed out to see the whole scene (or a significant portion of it), it will show parallax since you cannot remove it everywhere at the same time.
10-22-2019 12:25 AM
Thanks for the quick reply Yasmin - I understand how to change x and y parallax with keyboard (XY) and mouse (just wrote the wrong command down in my post - sorry). When i adjust X partallax and the elevation is now correct - you are right, i do not see the blue/red cursors as separate. I can also see they are sitting over the samepoint in the left/right windows. I understand that perfectly and that parallax cannot be removed everywhere - especially as elevation of the scene changes.
My question is relating to how SA displays this information.
If I use the mouseheel to raise or lower the floating cursor they then begin to seperate immediately in the stereo window, whereas in other software i woud have used the parallax also adjusts simultaneously (at a smaller increment) so the cursors stay together and you get the impression the cursor is raising/lowering.The way SA displays it I do not see the reason in using the floating cursor via the mouse wheel - i can simply adjust the x parallax with the keyboard and never need to use the mousewheel at all.
Thanks in advance.
10-22-2019 12:01 PM
You are correct, scroll wheel does not work the same way as it does in other IMAGINE Photogrammetry stereo applications such as Stereo Measurement tool and Terrain Editor. When you adjust the height with scroll wheel, in split views image moves and mouse stays at the center of the image. In Stereo View mouse will move up and down. You will need to adjust the parallax using keyboard's x and y keys and then do the fine tuning with scrool wheel because adjustment with scrool wheel is limited to certain number of pixels.
10-31-2019 02:33 PM
Yes, please adjust X parallax using 'x' key, and moving mouse horizontally. You may do the fine tuning with scroll wheel.
11-04-2019 12:45 AM
Thanks - it is important i understand this properly as am not familiar with the way SA presents this info and am concerned i have some toggle swtiched off (or on) when i shouldnt.
Am i correct in thinking the fine tuning is not done in the stereo window (1), but only in the bottom windows - 2 and 3 in my post? So after you adjust X parallax with the X key and mouse in window 1, you continuously check windows 2 and 3 as you are digitsing a feature. My concern is this - nothing changes in the stereo window (1) as i move the mousewheel, except that the cursors seperate. Should I not see them staying as one but raising/lowering? Should the red/blue not diverge/converge as well? What I am seeing is working as designed?
11-05-2019 12:55 PM
You have to use Anaglyph glasses to see the cursor raising or lowering. If you are looking with your naked eye, you will see them separting instead of going up/down.
a month ago
Hi Sam - am using the red/blue anaglyph glasses. Not a very expensive pair, but the Stereoview works fine.For now I can use the lower left right window. Thanks both for the help