[Gdal-dev] EHdr/ESRI .hdr to read SRTM is no longer working

[Joaquim Luis]

Markus Neteler wrote:
> Joaquim,
>
> if you add
> PIXELTYPE SIGNEDINT
> to the header file, it should work again.
>   


Thanks Markus
Yes it works

Joaquim Luis


> Markus
>
> On Tue, Apr 10, 2007 at 12:16:56PM +0100, Joaquim Luis wrote:
>   
>> Hi,
>> The recipe of reading SRTMs by generating a ESRI .hdr file is no longer 
>> working
>> with  GDAL1.4 but it does work with 1.3.2
>> The problem seams to be that data is converted to unsigned short int 
>> instead of signed short int.
>>
>> Joaquim Luis
>>
>>
>> ---------------- With GDAL1.4.0
>>
>> D:\programas\GDALB140\bin>gdalinfo -stats d:\img_samples\N18W071.hgt
>> Driver: EHdr/ESRI .hdr Labelled
>> Size is 1201, 1201
>> Coordinate System is `'
>> Origin = (-71.000416666666666,19.000416666666666)
>> Pixel Size = (0.000833333333333,-0.000833333333333)
>> Corner Coordinates:
>> Upper Left  ( -71.0004167,  19.0004167)
>> Lower Left  ( -71.0004167,  17.9995833)
>> Upper Right ( -69.9995833,  19.0004167)
>> Lower Right ( -69.9995833,  17.9995833)
>> Center      ( -70.5000000,  18.5000000)
>> Band 1 Block=1201x1 Type=UInt16, ColorInterp=Undefined
>>  Minimum=0.000, Maximum=65535.000, Mean=2873.507, StdDev=11834.425
>>  NoData Value=-32768
>>
>> ---------------- Now with GDAL1.3.2
>>
>>
>> D:\programas\GDALB132\bin>gdalinfo -stats d:\img_samples\N18W071.hgt
>> Driver: EHdr/ESRI .hdr Labelled
>> Size is 1201, 1201
>> Coordinate System is `'
>> Origin = (-71.000417,19.000417)
>> Pixel Size = (0.00083333,-0.00083333)
>> Corner Coordinates:
>> Upper Left  ( -71.0004167,  19.0004167)
>> Lower Left  ( -71.0004167,  17.9995833)
>> Upper Right ( -69.9995833,  19.0004167)
>> Lower Right ( -69.9995833,  17.9995833)
>> Center      ( -70.5000000,  18.5000000)
>> Band 1 Block=1201x1 Type=Int16, ColorInterp=Undefined
>>  Minimum=-39.000, Maximum=2833.000, Mean=459.681, StdDev=572.878
>>  NoData Value=-32768
>>  Metadata:
>>    STATISTICS_MINIMUM=-39
>>    STATISTICS_MAXIMUM=2833
>>    STATISTICS_MEAN=459.68081074608
>>    STATISTICS_STDDEV=572.87797657624
>>
>> and the header file is
>>
>> # N18W071.hdr
>>
>> BYTEORDER     M
>> LAYOUT        BIL
>> NROWS       1201
>> NCOLS       1201
>> NBANDS        1
>> NBITS         16
>> BANDROWBYTES  2402
>> TOTALROWBYTES 2402
>> BANDGAPBYTES  0
>> NODATA        -32768
>> ULXMAP        -71
>> ULYMAP        19
>> XDIM         0.000833333333333
>> YDIM         0.000833333333333
>>
>>     
>
>