We have a customer who has purchased an extensive library of aerial 
imagery that is in ECW format.  According to the Maptitude help 
system, ECW format is supported.  There is mention of an 
associated .ERS file that contains the header information.

These aerial photos do not have .ERS files.  rather, the header 
information is built into the file.  I confirmed this using a free 
utility from ER Mapper.

Ok, here is the problem.

I can open the aerial photo in Maptitude and can successfully add new 
layers to the map.  However, if i try to add an aerial photo to an 
existing map (the most common use case), the aerial photo will not 
appear.  It shows up in the layer list, but does not display on the 
map.  I have tried turning off every layer except the photo and it 
doesn't show up.

The only way i have been able to get this to work was by doing the 
following:

1.  Opening the image in the ER Mapper header editor to determine the 
projection (or using the GISDK to query the projection).  For the 
images i was testing, the projection was listed as "NUTM19."  I 
assumed that this meant "Universal Transverse Mercator" in "Zone 19."

2.  I explicitly set the projection for the map to be "UTM 19" and 
then attempted to add the aerial image.  This worked successfully.

The problem i am having is that this customer is concerned that the 
workflow is too cumbersome (i.e. having to open the image in another 
program to determine the projection first and then having to set that 
projection for the map).  They are recent MapInfo converts, which 
handled these image formats natively.  

According to the documentation, Maptitude is supposed to 
automatically lock the projection of the map to be the same as the 
projection for the image that has been added.  This would be fine.  I 
have confirmed that this works properly with other imagery formats 
(i.e. TIFF and Mr.Sid).  However, ECW seems not to work.

Is there something that can be done here?  I was thinking that the 
header file may be listing the projection using a code that Maptitude 
doesn't understand.  I would be willing to help the customer update 
the headers, if this will work.  However, i need to know what to 
update it to.

Another nugget of information:  Whenever i add an ECW file to the 
map, i receive the following error message:

"Major Axis or Radius = 0 not given.  Click OK to continue.  
Reference Info, lay_map,1070,0."

Any help would be greatly appreciated!

Thanks.

Michael





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