[Gvsig_english] Importing a raster image with gvSIG Mobile
Marcel Schoolmeesters
schoolmeesters at gmx.de
Tue Apr 5 00:30:17 CEST 2011
ok, but shouldn't gvsig mobile be able to do that on its own? as it
seems to do it after zooming 3x - why not in 0x/1x or 4x zoom? that's
what I wondered...and wanted to mention :) would be easier than resizing
the image wouldn't it.
Regards,
Marcel
Am 04.04.2011 08:40, schrieb Juan Lucas Dominguez Rubio:
> Hello,
> I used gdalwarp with the -tr param to change the resolution.
> The extent changes slightly due to roundings, I think, but the
> difference is in the order of the decimeters, which is less than the
> width of a pixel:
> Corner Coordinates:
> Upper Left ( 9.1256726, 53.4908082)
> Lower Left ( 9.1256726, 53.4750997)
> Upper Right ( 9.1744405, 53.4908082)
> Lower Right ( 9.1744405, 53.4750997)
> Center ( 9.1500566, 53.4829539)
> Corner Coordinates:
> Upper Left ( 9.1256726, 53.4908082)
> Lower Left ( 9.1256726, 53.4751060)
> Upper Right ( 9.1744369, 53.4908082)
> Lower Right ( 9.1744369, 53.4751060)
> Center ( 9.1500548, 53.4829571)
> The width/height ratio of the image has changed of course, because the
> pixel resolution has changed only in one of the axis (the X axis).
> Regards,
> Juan Lucas Domínguez Rubio
> ---
> Prodevelop SL, Valencia (España)
> Tlf.: 96.351.06.12 -- Fax: 96.351.09.68
> http://www.prodevelop.es <http://www.prodevelop.es/>
> ---
>
> ------------------------------------------------------------------------
> *De:* gvsig_internacional-bounces at listserv.gva.es en nombre de Marcel
> Schoolmeesters
> *Enviado el:* vie 01/04/2011 14:56
> *Para:* Users and Developers mailing list
> *Asunto:* Re: [Gvsig_english] Importing a raster image with gvSIG Mobile
>
> Hello,
>
> google coordinates are EPSG:3785, I think? (old name: EPSG:900913) -
> That was the easiest way to get coordinates. I have used the map for
> u-center (from u-blox), because of using that application for testing
> last year. So I easily could lookup zthe upper edge. I did not have
> any Desktop GIS installed, perhaps I should do that ;) but I will need
> a map of the region with identical points, don't I? or is it possibvle
> to transform by click and enter coordinates?
>
> Concerning your new map image: Did you change/rescale the image? it is
> not the same anymore, so the new worldfile cannot be compared.
>
> As mentioned before, the image is not in EPSG:4326 obviously,
> otherwise it would not have to be resized by gvSIG Mobile ;) and the
> ratio is not really small, I think...it is rather 0.5 in height or
> something surround it?
>
> Regards,
>
> Marcel
>
> Am 01.04.2011 09:22, schrieb Juan Lucas Dominguez Rubio:
>
> Hello, I have realized that in your JGW file the first and fourth
> parameters dont have the same absolute value:
> 1.073E-05
> 0
> 0
> -6.352E-06
> 9.125678
> 53.490805
> This is not wrong, but maybe the application is not dealing well
> with it.
> To create ECW images, I have used FWTools
> http://fwtools.maptools.org <http://fwtools.maptools.org/>
> - install
> - Start the command-line terminal from the new icon
> - move to the folder where the files are (cd ...)
> - type something like:
> gdal_translate -of ecw jpg-map.jpg ecw-map.ecw
> (JPG and JGW files in the current folder)
> I have recreated the JPG and JGW to have the same absolute value
> in the first and fourth parameters:
> https://correo.prodevelop.es/descarga/gvsig/mobile/new_map.zip
> Try that one and see if the image is ok now.
> More info:
> http://www.gdal.org/gdal_utilities.html
> http://www.gdal.org/ogr_utilities.html
> ************
> Apart from that, this is another consideration not related to the
> previous problem:
> How did you create that image? Your original JPG seems to be using
> a projected SRS (like Google's EPSG:900913 or the German EPSG:3146X).
> Did you simply compute the coordinates in EPSG:4326 of the corners
> and wrote the JGW file by hand? That would not be correct because
> there is not a linear relation between those SRS (in other words,
> the "rule of three" does not work with them). In this case, the
> error would be not visible because it's a small area (so actually
> that would be a simple, valid approximation), but it's always
> better to do a proper reprojection with gvSIG or FWTools, for example.
> Regards,
> Juan Lucas Domínguez Rubio
> ---
> Prodevelop SL, Valencia (España)
> Tlf.: 96.351.06.12 -- Fax: 96.351.09.68
> http://www.prodevelop.es <http://www.prodevelop.es/>
> ---
>
> ------------------------------------------------------------------------
> *De:* gvsig_internacional-bounces at listserv.gva.es en nombre de
> Marcel Schoolmeesters
> *Enviado el:* jue 31/03/2011 20:36
> *Para:* Users and Developers mailing list
> *Asunto:* Re: [Gvsig_english] Importing a raster image with gvSIG
> Mobile
>
> Hello,
>
>
> well, I have created the image for myself with google coordinates
> :-) and I've checked the coordinates of the image and of the
> cursor...of course....so definitely, it is the image, which is not
> scaled correctly each time, you can see when looking at those
> screenshots. The image must be compressed in height (using
> EPSG:4326) because of the location at 53° N...
>
> I've checked the ECW and it looks and works fine,....can you tell
> me the commands to create an ecw-file from worldfile? it is a
> commandline tool, right?
>
> And of course, you mention the "lot of things" the application is
> doing while zoom or pan....but the image is even not compressed in
> height being shown the first time (without any zoom)
>
> Well, I think that should be checked...if yomebody got time...it
> is not important to me at the moment...it might be nice to show
> some bugs, too :-) but don't know if it is planned to change in
> gvsig mobile 1.0?
>
>
> Regards
> Marcel
>
>
>
>
> Am 31.03.2011 19:10, schrieb Juan Lucas Dominguez Rubio:
>
> Hello,thanks for the files.
> I mean that when you do zoom and pan in gvSIG Mobile, the
> application does a lot of little things in order to draw the
> image using as little memory as possible, and if one of those
> steps is wrong, then the image might be misplaced, but I have
> never noticed this.
> I remember that there is a little bug that causes the GPS
> arrow to be misplaced when you do some zoom and pan: until the
> next GPS coordinates arrive (and refreshes the GPS arrow), it
> can be misplaced. Maybe that's the problem you noticed? Is the
> arrow misplaced even after you have received several new GPS
> coordinates?
> To find out who is misplaced (the image or the arrow) you can
> load a shapefile (which always is ok, I think).You can
> download some ECW and SHP of Bremenvorde from here:
> https://correo.prodevelop.es/descarga/gvsig/mobile/
> The files called "...31467..." are in EPSG:31467, in case you
> prefer those. I created them with GDAL and OGR, so I think
> they have a little error of 1 or 2 meters (which I think is
> not a problem in this case).
> So if you load the JPG, then the SHP and use the GPS, what
> happens?
> If the SHP and the JPG are consistent and the GPS is
> misplaced, then there is a bug related to the GPS
> arrow (temporarily? always?)
> If the GPS and the SHP are consistent and the JPG is not, then
> there is a problem with the WKR driver.
> Regards,
> Juan Lucas Domínguez Rubio
> ---
> Prodevelop SL, Valencia (España)
> Tlf.: 96.351.06.12 -- Fax: 96.351.09.68
> http://www.prodevelop.es <http://www.prodevelop.es/>
> ---
>
> ------------------------------------------------------------------------
> *De:* gvsig_internacional-bounces at listserv.gva.es en nombre de
> Marcel Schoolmeesters
> *Enviado el:* jue 31/03/2011 17:54
> *Para:* Users and Developers mailing list
> *Asunto:* Re: [Gvsig_english] Importing a raster image with
> gvSIG Mobile
>
> Hello.
>
> I know those performance problems. But _*if*_ the
> transformation is performed, it should _not_ be wrong I think
> :) better would be an error message which tells the user that
> the image is too big or something...
>
>
> I cannot upload the image (25MB *.png or 5MB *.jpg), but I
> have uploaded the jpg to rapidshare, instead. /(The png file
> is about 2MB too big, it won't even be loaded, so I did not
> upload it)/
>
> JPG: http://rapidshare.com/files/455277713/jpg-raster.zip
> ECW: http://rapidshare.com/files/455279357/ecw-map.ecw
>
>
> I have compressed the file to ecw, too, but it is not
> geo-referenced, I think. I tried AU ECW Compressor...because
> the manual says, it will add geo-information...but it
> doesn't....not from an extra worldfile.
>
> Well, to load the worldfile of the JPG, you need to change the
> getWorldFileExtensions() in WKFRasterDriver.java, I think. Or
> change the extension to *.wld... but I'm sure, you know.
> (however, jgw seems to be the default one, isn't it?)
>
>
> Regards,
>
> Marcel
>
>
>
>
> Am 31.03.2011 17:04, schrieb Juan Lucas Dominguez Rubio:
>
> Hello,
> When zooming in and out with a non-ECW image, the
> app performs some shift and clip operations to minimize
> the amount of memory needed. I have never seen
> any strange bevavior there, but there might be a bug, yes.
> gdal_translate (FWTools) is free and creates faster, more
> reliable ECW images.
> which format are you using?
> can you send the image to the list? (with the georef. file
> if it's not a ecw file)
> Regards,
> Juan Lucas Domínguez Rubio
> ---
> Prodevelop SL, Valencia (España)
> Tlf.: 96.351.06.12 -- Fax: 96.351.09.68
> http://www.prodevelop.es <http://www.prodevelop.es/>
> ---
>
> ------------------------------------------------------------------------
> *De:* gvsig_internacional-bounces at listserv.gva.es en
> nombre de Marcel Schoolmeesters
> *Enviado el:* jue 31/03/2011 16:51
> *Para:* Users and Developers mailing list
> *Asunto:* Re: [Gvsig_english] Importing a raster image
> with gvSIG Mobile
>
> Hey all,
>
> I've got new interesting findings :-)
>
> * The error of the height of the image does_not appear
> at all_ when I zoom *three *times.
> * When I zoom *twice*, the error appears_only in the
> middle _of the image, but not when I see the
> background of the Map! I cannot say exactly,...
> * But when I does not zoom or/*only once...or four
> times or more*/... the image is_not resized _I
> think...it is the original ratio....
>
> I have got some screenshots, so that you might understand
> it better :)
>
> Perhaps, it is a graphical bug? I don't know...perhaps,
> somebody's got an idea? would be cool to be fixed!
>
>
> Regards,
>
> Marcel
>
>
> Am 30.03.2011 16:42, schrieb Marcel Schoolmeesters:
>
> Thanks for the explanation.
>
> As I said, the ImageExt values are correct...(y is
> calculated by _y + _h, I think) .....I have debugged
> the data flow and everything is understandable up to
> this function (and afterwards. What the function is
> doing might be clear, and even the values of the
> viewRect, too,...after your little explanation, what
> should be self-evident :-)
>
> However, the final lower/left edge of the picture is
> not shown at 53.475096504° where it should be, but
> somewhere at 53.464...and I cannot find the code where
> this is calculated...(but better to say that I have
> given up because of so many steps...)
>
> Best regards,
>
> Marcel
>
>
> Am 30.03.2011 09:32, schrieb Juan Lucas Dominguez Rubio:
>
> Hello,
> that method computes the extent of the view when
> you add the first layer. The app knows the size of
> the screen and the extent of the layer, and their
> ratios are different, so you have to do a simple
> computation to find out the extent of the new view.
> Maybe you have misunderstood the extent of a layer
> and the extent of the view?
> When you add the first layer, the extent of the
> view is the smallest rectangle which contains the
> extent of the layer and, at the same
> time, respects the width/height ratio of the
> screen, of course.
> Regards,
> Juan Lucas Domínguez Rubio
> ---
> Prodevelop SL, Valencia (España)
> Tlf.: 96.351.06.12 -- Fax: 96.351.09.68
> http://www.prodevelop.es <http://www.prodevelop.es/>
> ---
>
> ------------------------------------------------------------------------
> *De:* gvsig_internacional-bounces at listserv.gva.es
> en nombre de Marcel Schoolmeesters
> *Enviado el:* mar 29/03/2011 21:20
> *Para:* Users and Developers mailing list
> *Asunto:* Re: [Gvsig_english] Importing a raster
> image with gvSIG Mobile
>
> well, I think the main problem of understanding is
> in function
> MapContext.*getExtentFromFullExtentAndImageSize*()
> ... I think the new height etc are calculated there?
>
> Am 29.03.2011 21:00, schrieb Marcel Schoolmeesters:
>
> Hello,
>
> I have tried to load a raster image (had to
> try jpg, because *.png did not even load), but
> I am getting a wrong position of the extent.
> Anybody got the same error?
>
> I have tried the debug mode, but there are too
> many functions to catch on. Perhaps anybody
> can help?
>
> Somewhere the map origin is changed from the
> upper edge to the lower edge, that far I could
> follow, but then the image extent (height) and
> the origin coords (of Y) has been changed.
> Why? it seems to be very hard to understand
> the whole way of building the image at the
> right place.
>
> However, in attachment the original rectangle
> and the changed one are shown with their
> values while debugging...
>
> The lower edge of the final image is
> positioned between those Y values (@ 53.464)
> but it needs to be positioned at 53.475....
>
> what is getRasterTansformation() actually doing?
>
>
> Thanks in advance, if anybody can help.
> However, that issue should be fixed, I think.
> The import of PNG is not even possible, as I
> mentioned before..
>
> Regards
>
> Marcel
>
>
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