open TELEMAC-MASCARET The mathematically superior suite of solvers

Hi Everyone,

I received an email recently regarding aerial images in Blue Kenue and thought the topic would be of general interest (hence this post)

I was at the recent Telemac User Conference in Chatou, and attended your workshop on Blue Kenue.

I was able to obtain a series of aerial photos in Jpeg2 format for my study site. And I was wondering whether or not it is possible to import aerial photos into Blue Kenue to make it easier to identify features or areas of interest in my mesh.

Blue Kenue supports tiff/GeoTIFF files and has a simple mechanism for geo-referencing an image.

1. Convert the JPEG to a TIFF file using any image program (eg. Windows PhotoEdit, IfranView, etc.).
2. Import the TIFF file into BlueKenue.
3. Open its Properties…
4. Go to the Spatial Tab to register the image spatially.
5. Set the Pixel Size and,
6. SouthWest corner coordinates.
7. Alternatively you can specify the 4 corners.
8. “Assign” the coordinate system.
9. Save the TIFF file (the geo-referencing information is saved in the header).

The image is now registered spatially.

Martin

Hi

The Martin solution is ok if the image is well oriented.
If this is not the cas, you could use another solution using Quantum GIS (a free and open GIS program)
You could open a raster and create your own referencing with 3 or 4 points. Quantum generate a GeoTiff file which could be use directly by Kenue

Hope this helps

Hi,

As I said this is a SIMPLE solution.

There are many sophisticated image processing and GIS applications that register and ortho-rectify images, correcting distortions due to things like topography, perspective, camera/lens combinations, atmospheric effects, etc. etc. It all depends on your needs.

Martin

Hi, I was wondering if it's possible to import tifs, jpgs, that are reference via a world file (tfw, jgw, ...).

Thanks,
Josh

Hi Josh,

Blue Kenue reads coordinate system information ONLY from the header of a GeoTIFF file. It does not attempt to parse the tfw file.

Regarding JPEG, see my comment above.

Cheers... Martin