On Sep 20, 1:00 pm, "Alvaro Paredes L." <alvaropared...@gmail.com>
wrote:
> On 20 sep, 10:24, Robert <robert.m...@gmail.com> wrote:
>
>
>
>
>
>> On Sep 20, 8:12 am, Jeremy Bailin <astroco...@gmail.com> wrote:
>
>>> On Sep 19, 11:14 pm, "Alvaro Paredes L." <alvaropared...@gmail.com>
>>> wrote:
>
>>>> Hi all
>
>>>> I was searching on the web, but i didn't find an answer to my problem.
>>>> I need to make asubseton animageusing
>
>>>> coordinates, but i can't find a way to do it. I see this method
>
>>>> http://groups.google.es/group/comp.lang.idl-pvwave/browse_fr m/thread/...
>>>> and this other (very
>
>>>> similar) http://www.mombu.com/programming/idl/t-subset-an-image-by-ro i-in-idl-...,
>>>> but don't use
>
>>>> coordinates, use an evf file.
>
>>>> IDL/ENVI has a widget that use only two coordinates to cut (upper-left
>>>> and lower-right coordinate), but it isn't
>
>>>> fully automatically.
>
>>>> Is there any function to cut theimagewith set coordinates and save
>>>> it in a new file?
>
>>>> I really hope you can help me... I'm not a programmer and this
>>>> sometimes it's very hard
>
>>>> Thanks!
>
>>>> Alvaro
>
>>> Do you mean like:
>
>>> newimage = oldimage[x0:x1,y0:y1]
>
>>> ?
>
>>> -Jeremy.
>
>> If the original author is looking tosubsetby map coordinates, he
>> needs to use the procedure
>
>> ENVI_CONVERT_FILE_COORDINATES, FID, XF, YF, XMap, YMap
>
>> to convert the corners of hisimagein map coordinates to file
>> coordinates. Once he has the proper file coordinates, he cansubset
>> theimage. If you give us a little more specifics of what you are
>> trying to do, we can probably provide more information.
>
>> r
>
> Thanks for the quickly help. I have an image with degrees coordinates
> and with the function that Robert suggested
> (ENVI_CONVERT_FILE_COORDINATES) i can transform coord to pixel value
> without problems (as the script i show below). But i try to do that
> Jeremy suggest, but i don't know if is it properly working
> (image=img_file[XF,YF]??)
>
> forward_function ENVI_CONVERT_FILE_COORDINATES
> pro SUBSET
> envi, /restore_base_save_files
> envi_batch_init,log_file='batch.txt'
>
> ; define the image to be opened
> img_file='F:\IMAGE\NDVI-HDF\try\NDVI_2008_03_02.img'
> envi_open_file,img_file,r_fid=fid
> print, 'fid=',fid
>
> ; define coordinates to make the subset
> YMap=[-32.6030694, -32.9797194]
> XMap=[-71.0580916, -70.5006694]
>
> ENVI_CONVERT_FILE_COORDINATES, FID, XF, YF, XMap, YMap
>
> ;rounds the pixel value to its closest integer.
> XF=ROUND(XF)
> YF=ROUND(YF)
>
> ;verify the conversion
> print, 'X pixel ',XF
> print, 'Y pixel ',YF
>
> ;making the subset??????
> image=img_file[XF,YF]
>
> ; Exit Envi
> envi_batch_exit
> end
>
> Finally, and maybe this is a basic question, how i save this "subset"
> in a .img file?
>
> Thanks!
>
> Alvaro
Note the colons in my example. :-)= Instead of
image=img_file[XF,YF]
you probably want:
image=img_file[XF[0]:XF[1], YF[0]:YF[1]]
-Jeremy.
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