[gdal-dev] PDF-->JPEG-->KML. Confused about association between KML bounding box and PDF's neatline and corner coordinates.

[Brent Fraser]

Hmmm.  My PDF doesn't seem to have a neatline, only a MediaBox and two 
BBoxes...

Brent

On 10/20/2010 9:04 AM, Even Rouault wrote:
> You don't need to convince anyone to add new functionnality. It already exists
> ;-)
>
> See the -cutline option of gdalwarp. Basically you use the NEATLINE reported by
> gdalinfo as the CUTLINE (that was the sole purpose of reporting the NEATLINE by
> the way !)
>
> The easiest way is to make a simple CSV like this :
>
> foo,WKT
> bla,"POLYGON((....))"
>
> and you paste the content of NEATLINE as the value of the WKT.
>
> and do a gdalwarp without reprojecting to crop (use -crop_to_cutline) to the
> neatline. Then you can do a 2nd gdalwarp to reproject to the target SRS.
>
> (if you want to do just one gdalwarp, you'll have to do ogr2ogr to reproject the
> cutline.csv into the target SRS)
>
> See http://gdal.org/gdalwarp.html and/or
> http://gdal.org/structGDALWarpOptions.html#0ed77f9917bb96c7a9aabd73d4d06e08
>
>
>> Boris,
>>
>>     Use gdalwarp to convert your jpeg to Geographic coordinates (I think
>> it needs to be converted for KML anyways):
>>
>> gdalwarp -t_srs EPSG:4326 in.jpg out.jpg
>>
>> then use gdalinfo to get the corner coordinates.
>>
>> Currently the entire page of the PDF is rendered into the image.
>> Perhaps we can convince Even to add an option to convert only the mapped
>> area (or mask everything else?)
>>
>> Best Regards,
>> Brent Fraser
>>
>> On 10/20/2010 8:07 AM, Boris Dev wrote:
>>> My objective is to make a KML ground overlay with a geospatial PDF map.
>>>
>>> Using GDAL's translate utility I have converted the PDF to a JPEG. The
>>> next step and problem for me is to write the text of the KML ground
>>> overlay, which requires a text of bounding box information like this:
>>>
>>> <LatLonBox>
>>>           <north>37.91904192681665</north>
>>>           <south>37.46543388598137</south>
>>>           <east>15.35832653742206</east>
>>>           <west>14.60128369746704</west>
>>>
>>>
>>>           <rotation>-0.1556640799496235</rotation>
>>>         </LatLonBox>
>>>
>>> As GDAL's output, I saw that the entire PDF with legend, title, etc
>>> and not just the map image was converted.
>>>
>>> As GDAL's output, I also saw 2 parts of data that seem they are useful
>>> to match a bounding box to the map within the jpeg, but I cant figure
>>> out the puzzle of how to make this work? Can I get the bounding box of
>>> the entire PDF image with this information below?
>>>
>>> Corner Coordinates:
>>> Upper Left  (  666937.758, 2024687.983)
>>> Lower Left  (  666991.811, 2018338.153)
>>> Upper Right (  674511.276, 2024754.795)
>>> Lower Right (  674565.328, 2018404.965)
>>> Center      (  670751.543, 2021546.474)
>>>
>>> <MDI key="NEATLINE">POLYGON ((672676.488065659650601
>>> 2019417.955749646294862,672636.091432046378031
>>> 2024030.267778463661671,667347.405745737953112
>>> 2023983.612156898481771,667385.539170471020043
>>> 2019370.524140953086317,672676.488065659650601
>>> 2019417.955749646294862,672676.488065659650601
>>> 2019417.955749646294862,672676.488065659650601
>>> 2019417.955749646294862,672676.488065659650601
>>> 2019417.955749646294862))</MDI>
>>>
>>> I realize the coordinate above need to be converted to lat/long to be
>>> a KML ground overlay onto Google Maps, which I think I can handle.
>>>
>>> But I am unsure if I need to extract the map image from the jpeg using
>>> the NEATLINE?
>>> How are the Corner Coordinates translated into a bounding box?
>>>
>>> Any suggestions?
>>>
>>>
>>> _______________________________________________
>>> gdal-dev mailing list
>>> gdal-dev at lists.osgeo.org
>>> http://lists.osgeo.org/mailman/listinfo/gdal-dev
>
>