Hi, Using v.rast.stats in grass6.3 both in cygwin and native windows,
v.rast.stats [EMAIL PROTECTED] layer=1 [EMAIL PROTECTED] colprefix=dem percentile=90 I get this error :/GRASS/scripts/v.rast.stats: r.cats: command not found I see no entry in the 6.3 manual on r.cats any ideas on using v.rast.stats? On Wed, May 21, 2008 at 2:44 AM, Jonathan Greenberg <[EMAIL PROTECTED]> wrote: > Juan: > > Some responses below: >> >> Well, that's exactly the problem, i cannot make a complete mosaic for the >> region i'm working on with only images taken on one day, and it adds >> another >> problem: the images do not overlay well... if they did, i would been able >> to >> do a radiometric normalization easily (as Johnattan Greenberg >> suggested)... >> >> > > By "do not overlay well" I assume you mean they aren't well orthorectified > to one another -- although I consider this a "must do" for mosaicking and > for any level of image-to-image work (because of the time savings), you > COULD manually pick PIFs in the overlap zone (e.g. you'd pick a point in the > reference image, then visually pick the corresponding pixel in the > uncorrected image) -- orthorectifying first saves you the time of having to > pick two points per image -- rather, you just pick one point. How many > images do you have in your mosaic? Image-to-image rectification with > landsat imagery is fairly painless, shouldn't take you much more than 30 > mins per image once you get going with it. > At any rate, once you pick your PIFs, you can use v.what.rast or starspan > (starspan.casil.ucdavis.edu) to get this data out to a table to do the > regression calculations. >> >> So my problem now is how to overlay landsat images taken in different >> days. >> I've already asked for help on this issue (with no solution so far; mail >> subject="mosaic with landsat geotiff"), so guess i'll resume that >> thread... >> >> > > >>> if it is simply an "automatic contrast" adjustment, you could linearly >>> interpolate between bands so they matched. (but then which is correct?) I >>> don't think it would be though, as LANDSAT has fixed calibration for each >>> band. >>> >> >> How's that? >> >> > > This is what I suggested as well -- the question of which one is "correct" > is somewhat moot -- your goal, as I understand it, is to have all of the > images in the same radiometric scale, so you can just pick one (usually one > that's in the middle of your mosaic, and often temporally at the "edge" of > your time period (either a very early or a very recent image). If >>> >>> if you run i.landsat.rgb on the two images with the same parameters do >>> they >>> match up well? >>> >> >> what do you mean with 'the same parameters'? (maybe "cropping >> intensity"...) >> >> >>> >>> that doesn't touch the values, only the colors, but it may >>> give you a clue about the cause of the difference. >>> >> >> How exactly? as an example, i can see a subtle difference in the color of >> water in a river as it pases on to another 'tile', but what does it means, >> i >> don't have a clue... (the values changes from: |32|40|86| to |20|26|69|, >> for >> bands 3, 2, 1 respectively) >> >> >>> >>> I guess the important thing is the ratio of the bands, not the exact >>> values >>> of one particular band. I take it you see a hard line at the boundary in >>> the processed image? >>> >> >> i suspect you mean the same as Johnattan G. with the radiometric >> normalization... anyway, i don't know what you mean with 'proccesed >> image'. >> The original images come with a null region as a result of the >> georreferencing, and after i use r.null -r to remove the NULL-value bitmap >> file, yes, there is a hard line in the boundary, but what would that mean? >> >> >> > > It just means your images aren't radiometrically normalized to one another. > If you correctly normalize them you won't see a line in the mosaic. >>> >>> Hamish >>> >> >> JM >> ------------------------------------------------------- >> _______________________________________________ >> grass-user mailing list >> [email protected] >> http://lists.osgeo.org/mailman/listinfo/grass-user >> >> > > -- > Jonathan A. Greenberg, PhD > Postdoctoral Scholar > Center for Spatial Technologies and Remote Sensing (CSTARS) > University of California, Davis > One Shields Avenue > The Barn, Room 250N > Davis, CA 95616 > Cell: 415-794-5043 > AIM: jgrn307, MSN: [EMAIL PROTECTED], Gchat: jgrn307 > > _______________________________________________ > grass-user mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/grass-user > -- |---------|----------------------------------------------------------| | __.-._ |"Ohhh. Great warrior. Wars not make one great." -Yoda | | '-._"7' |"Freedom is still the most radical idea of all" -N.Branden| | /'.-c |Linux registered user #402901, http://counter.li.org/ | | | /T |http://esambale.wikispaces.com| | _)_/LI |---------|----------------------------------------------------------| _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
