| Select Images based on vector/shapefile/ROI [message #87903] |
Mon, 03 March 2014 12:11  |
Sean Hartling
Messages: 4
Registered: March 2014
|
Junior Member |
|
|
Hi. I am working with MODIS data and I am attempting to find images (from several thousand) that encompass a specific geographic area (the state of Missouri). I was attempting to perform this using Layer Stack and Subset via ROI in ENVI. However, due to the fact that the images do not have a common geographic range, ENVI adds 0.0 data values (instead of NaN, which would be helpful) where it adds extent to each image to encompass the all the image ranges. These 0.0 values will affect my overall calculations when I attempt to pull average pixel values over the specific time period.
I would like to select images where the vector file for Missouri falls entirely within an image and omit images where it does not. Is there an IDL code, or other method) that would help facilitate this?
I appreciate any help. Thanks!
|
|
|
|
|
|
|
|
| Re: Select Images based on vector/shapefile/ROI [message #87990 is a reply to message #87903] |
Mon, 10 March 2014 12:12  |
PMan
Messages: 61
Registered: January 2011
|
Member |
|
|
On Monday, March 3, 2014 3:11:56 PM UTC-5, Sean Hartling wrote:
> Hi. I am working with MODIS data and I am attempting to find images (from several thousand) that encompass a specific geographic area (the state of Missouri). I was attempting to perform this using Layer Stack and Subset via ROI in ENVI. However, due to the fact that the images do not have a common geographic range, ENVI adds 0.0 data values (instead of NaN, which would be helpful) where it adds extent to each image to encompass the all the image ranges. These 0.0 values will affect my overall calculations when I attempt to pull average pixel values over the specific time period.
>
>
>
> I would like to select images where the vector file for Missouri falls entirely within an image and omit images where it does not. Is there an IDL code, or other method) that would help facilitate this?
>
>
>
> I appreciate any help. Thanks!
Envi allows "No data Values" I believe, set in the header file. If you set that (to say -1 or NAN), then do your resize, does this populate the extra data to the no data values? you might need to convert to ENVI format first.
|
|
|
|
comp.lang.idl-pvwave archive
Members
Search
Help
Login
Home
