comp.lang.idl-pvwave archive - RDF feed
type: channel
description: Messages from Usenet group comp.lang.idl-pvwave, compiled by Paulo Penteado
items: Re: write_gif problem: Garbled Image

Re: write_gif problem: Garbled Image
type: item
description: Hi, I seem to have solved my problem. I was switching to a different workspace on my desktop (I have 6 workspaces on my FVWM desktop). Apperently this is not allowed, ie the window must be on the presently displayed screen to be tvrd()'d. Perhaps that should have been obvious, but it is a bummer because I like to switch to another workspace while this lenghthy progam completes, now I will just have to wait for it, or try to fit additional work onto this desktop. Regards, Chris McCarthy Chris McCarthy wrote: > > Hi Folks, > > I'm making .gifs of my data using write_gif > after grabing the display using tvrd() (data are > displayed using the "display.pro", similar to "tv", > then annotated) > > With a single program I generate 8 images, and occasionally > one of the .gifs comes out 80% garbled. Top 20% is > ok. I get the error message: > > % TVRD: Unable to create X windows Window completely > off screen, nothing read. > > Here's an examples: > > Normal Image: > http://www.astro.ucla.edu/~chris/gif/HD110463K.ON7.gif > > Garbled Image: > http://www.astro.ucla.edu/~chris/gif/HD110463K.ON6.gif > > In all cases I am watching the displayed images and they > look fine. Seems that tvrd() is having a problem with them > but why? Any ideas would be great. Thanks a lot > > Chris McCarthy > UCLA Astronomy
creator: Chris McCarthy
date: 1999-06-15T07:00:00-00:00

Re: write_gif problem: Garbled Image
type: item
description: Chris McCarthy wrote: > > Hi Folks, > > I'm making .gifs of my data using write_gif > after grabing the display using tvrd() (data are > displayed using the "display.pro", similar to "tv", > then annotated) > > With a single program I generate 8 images, and occasionally > one of the .gifs comes out 80% garbled. Top 20% is > ok. I get the error message: > > % TVRD: Unable to create X windows Window completely > off screen, nothing read. <http references to example images snipped> > > In all cases I am watching the displayed images and they > look fine. Seems that tvrd() is having a problem with them > but why? Any ideas would be great. Thanks a lot > > Chris McCarthy > UCLA Astronomy Chris - TVRD has problems reading a scrollable draw widget, and can have problems reading a window if it is iconified or obscured, at least under X windows. I believe David Fanning has an article on this at his website: www.dfanning.com . You might try an approach I've used in a SAFE_TVRD(), which creates a new pixmap window, uses DISPLAY, COPY=[] to copy the window into the pixmap, and then uses TVRD() to read from the pixmap. Seems to work in all situations. If there is a more straightforward approach to this problem I'd love to see it. Here's the code: ;------- Cut here ------------------------------------------------- ; SAFE_TVRD.PRO 6-11-97 DSFoster ; ; This function is a safer version of IDL's TVRD() function. First, ; there was a bug related to the reading from a scrollable draw. Also, ; the TVRD() function uses an X routine that has problems if the ; window is obscured or iconified. This routine uses the DEVICE, COPY= ; command to first copy the window contents to a new window pixmap, ; and then reads from this pixmap into the array. ; ; Modifications ; ; 6-11-97 DSF Check validity of draw widget. FUNCTION safe_tvrd, draw_widget, xsize, ysize on_error, 2 if (widget_info(draw_widget, /valid_id) eq 0) then begin return, -1 endif else if (widget_info(draw_widget, /name) ne 'DRAW') t…
creator: David Foster
date: 1999-06-15T07:00:00-00:00