Problem correctly reading Mapinfo TIF and TAB files into QGIS

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Problem correctly reading Mapinfo TIF and TAB files into QGIS

David Addy
In this area of the UK, a number of local authorities use Mapinfo for their Archaeology and Record Office services. This often involves reading historical maps in order to compare with current conditions on the ground. All such maps are calibrated within Mapinfo, and are usually in the form of .TIF files accompanied by a .TAB file giving the georeferencing data. As these departments are constantly under budgetary pressure there are many applications where the use of QGIS could result in considerable cost savings. However, it is necessary that existing maps should be easily read by QGIS and correctly located,
without a cumbersome file conversion process.
An example of such maps is the 1880s First Series 1:2500 scale county Ordnance Survey maps for Suffolk. At this scale it takes a large number of tiles to cover a whole county. In a sample dozen of such maps around Bury St Edmunds, only four were correctly located by QGIS. My mapping friend Nick Hopton has kindly addressed this problem to the GDAL forum, using two sample tiles, one of which works in QGIS and the other does not. The discussion on this is reproduced below, and appears to come down to the size of the error found by GDAL in its attempted transformation. AS this error seems to be acceptable within Mapinfo, I do not quite understand why it cannot work equally well within QGIS.
Obviously this must be a critical issue for all Mapinfo users who would like to adopt QGIS, but find that this problem causes their evaluations to fail at the first hurdle. Like myself, these users are not experts in the technical details of map projections, nor the problems of making pre-1936 maps fit within today's UK Ordnance Survey OSGB36 Grid References.
However, we need to know whether  anyone knows how to persuade QGIS/GDAL to locate these tiles in the correct place please?

--------------------------------------------------
PROBLEM PREVIOUSLY ADDRESSED TO GDAL FORUM:

A friend, a relative newcomer to GIS, is having problems loading some of the TIFs created with Mapinfo into QGIS. Each TIF has a TAB file and in some cases the TAB file is interpreted correctly and in other cases the TAB file is (apparently) not recognised.
I think this might be a problem with Gdal rather than a problem with QGIS. Taking just two of the TIFs, the output from gdalinfo when run on 33044061.TIF indicates that things are working as they should. However, when gdalinfo is run on 33044071.TIF the spatial data in its TAB file is not recognised. See the listings below.

The strange thing is that all of the TIFs can successfully be converted from TIF to GeoTIFF using gdalwarp. (But it is important to my friend that he should be able to open Mapinfo raster images directly.)

Any ideas?

Regards,
Nick.  


Contents of 33044061.TAB:
------------------------
!table
!version 300
!charset WindowsLatin1

Definition Table
  File "33044061.tif"
  Type "RASTER"
  (582429,263569) (1,7594) Label "Pt 1",
  (582372,265177) (1,0) Label "Pt 2",
  (584784,265263) (11335,1) Label "Pt 3",
  (584841,263655) (11335,7594) Label "Pt 4"
  CoordSys Earth Projection 8, 79, "m", -2, 49, 0.9996012717, 400000, -100000
  Units "m"

Results of running gdalinfo on 33044061.TIF:
-------------------------------------------
nick@nick-6150M2MA:~/Desktop/tabstuff$ gdalinfo 33044061.TIF
Warning 1: TIFFFetchNormalTag:ASCII value for tag "ImageDescription" contains null byte in value; value incorrectly truncated
during reading due to implementation limitations
Driver: GTiff/GeoTIFF
Files: 33044061.TIF
Size is 11335, 7594
Coordinate System is:
PROJCS["unnamed",
    GEOGCS["unnamed",
        DATUM["OSGB_1936",
            SPHEROID["Airy 1930",6377563.396,299.3249646],
            TOWGS84[375,-111,431,-0,-0,-0,0]],
        PRIMEM["Greenwich",0],
        UNIT["degree",0.0174532925199433]],
    PROJECTION["Transverse_Mercator"],
    PARAMETER["latitude_of_origin",49],
    PARAMETER["central_meridian",-2],
    PARAMETER["scale_factor",0.9996012717],
    PARAMETER["false_easting",400000],
    PARAMETER["false_northing",-100000],
    UNIT["Meter",1]]
GeoTransform =
  582371.785312838, 0.2128106799708935, 0.007506419931892793
  265177.0453393974, 0.007597130759524194, -0.2117600570261751
Metadata:
  TIFFTAG_IMAGEDESCRIPTION=
  TIFFTAG_XRESOLUTION=300
  TIFFTAG_YRESOLUTION=300
  TIFFTAG_MINSAMPLEVALUE=0
  TIFFTAG_MAXSAMPLEVALUE=1
  TIFFTAG_RESOLUTIONUNIT=2 (pixels/inch)
Image Structure Metadata:
  COMPRESSION=CCITTFAX4
  INTERLEAVE=BAND
  MINISWHITE=YES
Corner Coordinates:
Upper Left  (  582371.785,  265177.045) (  0d40'19.83"E, 52d15'14.75"N)
Lower Left  (  582428.789,  263568.939) (  0d40'19.71"E, 52d14'22.68"N)
Upper Right (  584783.994,  265263.159) (  0d42'27.09"E, 52d15'14.63"N)
Lower Right (  584840.998,  263655.053) (  0d42'26.92"E, 52d14'22.57"N)
Center      (  583606.392,  264416.049) (  0d41'23.39"E, 52d14'48.66"N)
Band 1 Block=512x512 Type=Byte, ColorInterp=Palette
  Image Structure Metadata:
    NBITS=1
  Color Table (RGB with 2 entries)
    0: 255,255,255,255
    1: 0,0,0,255
nick@nick-6150M2MA:~/Desktop/tabstuff$

Contents of 33044071.TAB:
------------------------
!table
!version 300
!charset WindowsLatin1

Definition Table
  File "33044071.tif"
  Type "RASTER"
  (584841,263655) (1,7576) Label "Pt 1",
  (584784,265263) (1,0) Label "Pt 2",
  (587197,265349) (11335,1) Label "Pt 3",
  (587254,263740) (11335,7576) Label "Pt 4"
  CoordSys Earth Projection 8, 79, "m", -2, 49, 0.9996012717, 400000, -100000
  Units "m"

Results of running gdalinfo on 33044071.TIF:
-------------------------------------------
nick@nick-6150M2MA:~/Desktop/tabstuff$ gdalinfo 33044071.TIF
Warning 1: TIFFFetchNormalTag:ASCII value for tag "ImageDescription" contains null byte in value; value incorrectly truncated
during reading due to implementation limitations
Driver: GTiff/GeoTIFF
Files: 33044071.TIF
Size is 11335, 7576
Coordinate System is `'
GCP Projection =
PROJCS["unnamed",
    GEOGCS["unnamed",
        DATUM["OSGB_1936",
            SPHEROID["Airy 1930",6377563.396,299.3249646],
            TOWGS84[375,-111,431,-0,-0,-0,0]],
        PRIMEM["Greenwich",0],
        UNIT["degree",0.0174532925199433]],
    PROJECTION["Transverse_Mercator"],
    PARAMETER["latitude_of_origin",49],
    PARAMETER["central_meridian",-2],
    PARAMETER["scale_factor",0.9996012717],
    PARAMETER["false_easting",400000],
    PARAMETER["false_northing",-100000],
    UNIT["Meter",1]]
GCP[  0]: Id=Pt 1, Info=
          (1,7576) -> (584841,263655,0)
GCP[  1]: Id=Pt 2, Info=
          (1,0) -> (584784,265263,0)
GCP[  2]: Id=Pt 3, Info=
          (11335,1) -> (587197,265349,0)
GCP[  3]: Id=Pt 4, Info=
          (11335,7576) -> (587254,263740,0)
Metadata:
  TIFFTAG_IMAGEDESCRIPTION=
  TIFFTAG_XRESOLUTION=300
  TIFFTAG_YRESOLUTION=300
  TIFFTAG_MINSAMPLEVALUE=0
  TIFFTAG_MAXSAMPLEVALUE=1
  TIFFTAG_RESOLUTIONUNIT=2 (pixels/inch)
Image Structure Metadata:
  COMPRESSION=CCITTFAX4
  INTERLEAVE=BAND
  MINISWHITE=YES
Corner Coordinates:
Upper Left  (    0.0,    0.0)
Lower Left  (    0.0, 7576.0)
Upper Right (11335.0,    0.0)
Lower Right (11335.0, 7576.0)
Center      ( 5667.5, 3788.0)
Band 1 Block=512x512 Type=Byte, ColorInterp=Palette
  Image Structure Metadata:
    NBITS=1
  Color Table (RGB with 2 entries)
    0: 255,255,255,255
    1: 0,0,0,255
-------------------------------------------------------------------


FRANK WARMERDAM REPLIED:


Nick,

I haven't tried the .TAB files locally, but I see they are both resulting in georeferencing info.  The one is expressed as a

geotransform with rotation and shear while the other is expressed as ground control points.

I believe that the .TAB reader attempts to compute a geotransform from the points in the TAB and if it can do so with minimal

error then that is what is returned - a solution easier to utilize in QGIS and other applications.

If the control points do not represent a clean affine transformation for the image then it falls back to returning them as

ground control points which relatively few applications can utilize directly.  

One "solution" is to run gdalwarp to transform the image that isn't currently working so well into a north up affine

transformation style image.
 eg.

gdalwarp 33044071.TIF 33044071_northup.TIF

This warp will be done using the control points (ironically also using a best fit first order polynomial).

The code responsible for the decision is this from gdal/gcore/gdal_misc.cpp:


/* -------------------------------------------------------------------- */

/*      Try to convert the GCPs into a geotransform definition, if      */

/*      possible.  Otherwise we will need to use them as GCPs.          */

/* -------------------------------------------------------------------- */

    if( !GDALGCPsToGeoTransform( nCoordinateCount, asGCPs, padfGeoTransform,

                                 FALSE ) )

    {

        if (pnGCPCount && ppasGCPs)

        {

            CPLDebug( "GDAL",

                "GDALLoadTabFile(%s) found file, wasn't able to derive a\n"

                "first order geotransform.  Using points as GCPs.",

                pszFilename );




            *ppasGCPs = (GDAL_GCP *)

                CPLCalloc( sizeof(GDAL_GCP),nCoordinateCount );

            memcpy( *ppasGCPs, asGCPs, sizeof(GDAL_GCP) * nCoordinateCount );

            *pnGCPCount = nCoordinateCount;

        }

    }

    else

    {

        GDALDeinitGCPs( nCoordinateCount, asGCPs );

    }

 I suspect if you change the FALSE to TRUE in the arguments to GDALGCPsToGeoTransform() you wlil always get an affine

transform even when it is not a very good fit.
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Re: Problem correctly reading Mapinfo TIF and TAB files into QGIS

Andre Joost
Am 27.12.2013 19:31, schrieb David Addy:

> However, we need to know whether  anyone knows how to persuade QGIS/GDAL to
> locate these tiles in the correct place please?
>

Have you tried working with virtual rasters? You can either build one
for every tif file, or an index VRT file for all you have, or even an
index on the virtual rasters from the first step.

You can run gdalwarp on the virtual raster without changing the original
file.

HTH,
André Joost


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Re: Problem correctly reading Mapinfo TIF and TAB files into QGIS

Bo Victor Thomsen
In reply to this post by David Addy
Nick -

Could you make a couple of "problem" and "no problem" tiff/tab files
available ?

Regards
Bo Victor Thomsen
Aestas-GIS
Denamrk

Den 27-12-2013 19:31, David Addy skrev:

> In this area of the UK, a number of local authorities use Mapinfo for their
> Archaeology and Record Office services. This often involves reading
> historical maps in order to compare with current conditions on the ground.
> All such maps are calibrated within Mapinfo, and are usually in the form of
> .TIF files accompanied by a .TAB file giving the georeferencing data. As
> these departments are constantly under budgetary pressure there are many
> applications where the use of QGIS could result in considerable cost
> savings. However, it is necessary that existing maps should be easily read
> by QGIS and correctly located,
> without a cumbersome file conversion process.
> An example of such maps is the 1880s First Series 1:2500 scale county
> Ordnance Survey maps for Suffolk. At this scale it takes a large number of
> tiles to cover a whole county. In a sample dozen of such maps around Bury St
> Edmunds, only four were correctly located by QGIS. My mapping friend Nick
> Hopton has kindly addressed this problem to the GDAL forum, using two sample
> tiles, one of which works in QGIS and the other does not. The discussion on
> this is reproduced below, and appears to come down to the size of the error
> found by GDAL in its attempted transformation. AS this error seems to be
> acceptable within Mapinfo, I do not quite understand why it cannot work
> equally well within QGIS.
> Obviously this must be a critical issue for all Mapinfo users who would like
> to adopt QGIS, but find that this problem causes their evaluations to fail
> at the first hurdle. Like myself, these users are not experts in the
> technical details of map projections, nor the problems of making pre-1936
> maps fit within today's UK Ordnance Survey OSGB36 Grid References.
> However, we need to know whether  anyone knows how to persuade QGIS/GDAL to
> locate these tiles in the correct place please?
>
> --------------------------------------------------
> PROBLEM PREVIOUSLY ADDRESSED TO GDAL FORUM:
>
> A friend, a relative newcomer to GIS, is having problems loading some of the
> TIFs created with Mapinfo into QGIS. Each TIF has a TAB file and in some
> cases the TAB file is interpreted correctly and in other cases the TAB file
> is (apparently) not recognised.
> I think this might be a problem with Gdal rather than a problem with QGIS.
> Taking just two of the TIFs, the output from gdalinfo when run on
> 33044061.TIF indicates that things are working as they should. However, when
> gdalinfo is run on 33044071.TIF the spatial data in its TAB file is not
> recognised. See the listings below.
>
> The strange thing is that all of the TIFs can successfully be converted from
> TIF to GeoTIFF using gdalwarp. (But it is important to my friend that he
> should be able to open Mapinfo raster images directly.)
>
> Any ideas?
>
> Regards,
> Nick.
>
>
> Contents of 33044061.TAB:
> ------------------------
> !table
> !version 300
> !charset WindowsLatin1
>
> Definition Table
>    File "33044061.tif"
>    Type "RASTER"
>    (582429,263569) (1,7594) Label "Pt 1",
>    (582372,265177) (1,0) Label "Pt 2",
>    (584784,265263) (11335,1) Label "Pt 3",
>    (584841,263655) (11335,7594) Label "Pt 4"
>    CoordSys Earth Projection 8, 79, "m", -2, 49, 0.9996012717, 400000,
> -100000
>    Units "m"
>
> Results of running gdalinfo on 33044061.TIF:
> -------------------------------------------
> nick@nick-6150M2MA:~/Desktop/tabstuff$ gdalinfo 33044061.TIF
> Warning 1: TIFFFetchNormalTag:ASCII value for tag "ImageDescription"
> contains null byte in value; value incorrectly truncated
> during reading due to implementation limitations
> Driver: GTiff/GeoTIFF
> Files: 33044061.TIF
> Size is 11335, 7594
> Coordinate System is:
> PROJCS["unnamed",
>      GEOGCS["unnamed",
>          DATUM["OSGB_1936",
>              SPHEROID["Airy 1930",6377563.396,299.3249646],
>              TOWGS84[375,-111,431,-0,-0,-0,0]],
>          PRIMEM["Greenwich",0],
>          UNIT["degree",0.0174532925199433]],
>      PROJECTION["Transverse_Mercator"],
>      PARAMETER["latitude_of_origin",49],
>      PARAMETER["central_meridian",-2],
>      PARAMETER["scale_factor",0.9996012717],
>      PARAMETER["false_easting",400000],
>      PARAMETER["false_northing",-100000],
>      UNIT["Meter",1]]
> GeoTransform =
>    582371.785312838, 0.2128106799708935, 0.007506419931892793
>    265177.0453393974, 0.007597130759524194, -0.2117600570261751
> Metadata:
>    TIFFTAG_IMAGEDESCRIPTION=
>    TIFFTAG_XRESOLUTION=300
>    TIFFTAG_YRESOLUTION=300
>    TIFFTAG_MINSAMPLEVALUE=0
>    TIFFTAG_MAXSAMPLEVALUE=1
>    TIFFTAG_RESOLUTIONUNIT=2 (pixels/inch)
> Image Structure Metadata:
>    COMPRESSION=CCITTFAX4
>    INTERLEAVE=BAND
>    MINISWHITE=YES
> Corner Coordinates:
> Upper Left  (  582371.785,  265177.045) (  0d40'19.83"E, 52d15'14.75"N)
> Lower Left  (  582428.789,  263568.939) (  0d40'19.71"E, 52d14'22.68"N)
> Upper Right (  584783.994,  265263.159) (  0d42'27.09"E, 52d15'14.63"N)
> Lower Right (  584840.998,  263655.053) (  0d42'26.92"E, 52d14'22.57"N)
> Center      (  583606.392,  264416.049) (  0d41'23.39"E, 52d14'48.66"N)
> Band 1 Block=512x512 Type=Byte, ColorInterp=Palette
>    Image Structure Metadata:
>      NBITS=1
>    Color Table (RGB with 2 entries)
>      0: 255,255,255,255
>      1: 0,0,0,255
> nick@nick-6150M2MA:~/Desktop/tabstuff$
>
> Contents of 33044071.TAB:
> ------------------------
> !table
> !version 300
> !charset WindowsLatin1
>
> Definition Table
>    File "33044071.tif"
>    Type "RASTER"
>    (584841,263655) (1,7576) Label "Pt 1",
>    (584784,265263) (1,0) Label "Pt 2",
>    (587197,265349) (11335,1) Label "Pt 3",
>    (587254,263740) (11335,7576) Label "Pt 4"
>    CoordSys Earth Projection 8, 79, "m", -2, 49, 0.9996012717, 400000,
> -100000
>    Units "m"
>
> Results of running gdalinfo on 33044071.TIF:
> -------------------------------------------
> nick@nick-6150M2MA:~/Desktop/tabstuff$ gdalinfo 33044071.TIF
> Warning 1: TIFFFetchNormalTag:ASCII value for tag "ImageDescription"
> contains null byte in value; value incorrectly truncated
> during reading due to implementation limitations
> Driver: GTiff/GeoTIFF
> Files: 33044071.TIF
> Size is 11335, 7576
> Coordinate System is `'
> GCP Projection =
> PROJCS["unnamed",
>      GEOGCS["unnamed",
>          DATUM["OSGB_1936",
>              SPHEROID["Airy 1930",6377563.396,299.3249646],
>              TOWGS84[375,-111,431,-0,-0,-0,0]],
>          PRIMEM["Greenwich",0],
>          UNIT["degree",0.0174532925199433]],
>      PROJECTION["Transverse_Mercator"],
>      PARAMETER["latitude_of_origin",49],
>      PARAMETER["central_meridian",-2],
>      PARAMETER["scale_factor",0.9996012717],
>      PARAMETER["false_easting",400000],
>      PARAMETER["false_northing",-100000],
>      UNIT["Meter",1]]
> GCP[  0]: Id=Pt 1, Info=
>            (1,7576) -> (584841,263655,0)
> GCP[  1]: Id=Pt 2, Info=
>            (1,0) -> (584784,265263,0)
> GCP[  2]: Id=Pt 3, Info=
>            (11335,1) -> (587197,265349,0)
> GCP[  3]: Id=Pt 4, Info=
>            (11335,7576) -> (587254,263740,0)
> Metadata:
>    TIFFTAG_IMAGEDESCRIPTION=
>    TIFFTAG_XRESOLUTION=300
>    TIFFTAG_YRESOLUTION=300
>    TIFFTAG_MINSAMPLEVALUE=0
>    TIFFTAG_MAXSAMPLEVALUE=1
>    TIFFTAG_RESOLUTIONUNIT=2 (pixels/inch)
> Image Structure Metadata:
>    COMPRESSION=CCITTFAX4
>    INTERLEAVE=BAND
>    MINISWHITE=YES
> Corner Coordinates:
> Upper Left  (    0.0,    0.0)
> Lower Left  (    0.0, 7576.0)
> Upper Right (11335.0,    0.0)
> Lower Right (11335.0, 7576.0)
> Center      ( 5667.5, 3788.0)
> Band 1 Block=512x512 Type=Byte, ColorInterp=Palette
>    Image Structure Metadata:
>      NBITS=1
>    Color Table (RGB with 2 entries)
>      0: 255,255,255,255
>      1: 0,0,0,255
> -------------------------------------------------------------------
>
>
> FRANK WARMERDAM REPLIED:
>
>
> Nick,
>
> I haven't tried the .TAB files locally, but I see they are both resulting in
> georeferencing info.  The one is expressed as a
>
> geotransform with rotation and shear while the other is expressed as ground
> control points.
>
> I believe that the .TAB reader attempts to compute a geotransform from the
> points in the TAB and if it can do so with minimal
>
> error then that is what is returned - a solution easier to utilize in QGIS
> and other applications.
>
> If the control points do not represent a clean affine transformation for the
> image then it falls back to returning them as
>
> ground control points which relatively few applications can utilize
> directly.
>
> One "solution" is to run gdalwarp to transform the image that isn't
> currently working so well into a north up affine
>
> transformation style image.
>   eg.
>
> gdalwarp 33044071.TIF 33044071_northup.TIF
>
> This warp will be done using the control points (ironically also using a
> best fit first order polynomial).
>
> The code responsible for the decision is this from gdal/gcore/gdal_misc.cpp:
>
>
> /* -------------------------------------------------------------------- */
>
> /*      Try to convert the GCPs into a geotransform definition, if      */
>
> /*      possible.  Otherwise we will need to use them as GCPs.          */
>
> /* -------------------------------------------------------------------- */
>
>      if( !GDALGCPsToGeoTransform( nCoordinateCount, asGCPs, padfGeoTransform,
>
>                                   FALSE ) )
>
>      {
>
>          if (pnGCPCount && ppasGCPs)
>
>          {
>
>              CPLDebug( "GDAL",
>
>                  "GDALLoadTabFile(%s) found file, wasn't able to derive a\n"
>
>                  "first order geotransform.  Using points as GCPs.",
>
>                  pszFilename );
>
>
>
>
>              *ppasGCPs = (GDAL_GCP *)
>
>                  CPLCalloc( sizeof(GDAL_GCP),nCoordinateCount );
>
>              memcpy( *ppasGCPs, asGCPs, sizeof(GDAL_GCP) * nCoordinateCount
> );
>
>              *pnGCPCount = nCoordinateCount;
>
>          }
>
>      }
>
>      else
>
>      {
>
>          GDALDeinitGCPs( nCoordinateCount, asGCPs );
>
>      }
>
>   I suspect if you change the FALSE to TRUE in the arguments to
> GDALGCPsToGeoTransform() you wlil always get an affine
>
> transform even when it is not a very good fit.
>
>
>
> --
> View this message in context: http://osgeo-org.1560.x6.nabble.com/Problem-correctly-reading-Mapinfo-TIF-and-TAB-files-into-QGIS-tp5095647.html
> Sent from the Quantum GIS - User mailing list archive at Nabble.com.
> _______________________________________________
> Qgis-user mailing list
> [hidden email]
> http://lists.osgeo.org/mailman/listinfo/qgis-user

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RE: Problem correctly reading Mapinfo TIF and TAB files into QGIS

David Addy

Hi Bo Victor,

Thanks for your reply to my enquiry. The two files referred to in the discussion are attached.

I hope that this helps you.

I do not know how to make these generally available to the whole  QGIS list, so I am  sending them to you off list.

Best wishes,

David

 

David Addy

10 Northgate Avenue

Bury St Edmunds

Suffolk

IP32 6BB

 

Telephone 01284 704247

Mobile      07766 178 459

 

Are you interested in the local history of West Suffolk? If so, try my local history site at:-

http://www.stedmundsburychronicle.com/index.htm

 

And including new for 2014, a picture gallery of  our area during the Great War, 1914-1919

http://www.stedmundsburychronicle.com/galleryww1/galleryww1home.htm

 

 

 

From: Bo Victor Thomsen [via OSGeo.org] [mailto:[hidden email]]
Sent: 28 December 2013 09:33
To: David Addy
Subject: Re: Problem correctly reading Mapinfo TIF and TAB files into QGIS

 

Nick -

Could you make a couple of "problem" and "no problem" tiff/tab files
available ?

Regards
Bo Victor Thomsen
Aestas-GIS
Denamrk

Den 27-12-2013 19:31, David Addy skrev:


> In this area of the UK, a number of local authorities use Mapinfo for their
> Archaeology and Record Office services. This often involves reading
> historical maps in order to compare with current conditions on the ground.
> All such maps are calibrated within Mapinfo, and are usually in the form of
> .TIF files accompanied by a .TAB file giving the georeferencing data. As
> these departments are constantly under budgetary pressure there are many
> applications where the use of QGIS could result in considerable cost
> savings. However, it is necessary that existing maps should be easily read
> by QGIS and correctly located,
> without a cumbersome file conversion process.
> An example of such maps is the 1880s First Series 1:2500 scale county
> Ordnance Survey maps for Suffolk. At this scale it takes a large number of
> tiles to cover a whole county. In a sample dozen of such maps around Bury St
> Edmunds, only four were correctly located by QGIS. My mapping friend Nick
> Hopton has kindly addressed this problem to the GDAL forum, using two sample
> tiles, one of which works in QGIS and the other does not. The discussion on
> this is reproduced below, and appears to come down to the size of the error
> found by GDAL in its attempted transformation. AS this error seems to be
> acceptable within Mapinfo, I do not quite understand why it cannot work
> equally well within QGIS.
> Obviously this must be a critical issue for all Mapinfo users who would like
> to adopt QGIS, but find that this problem causes their evaluations to fail
> at the first hurdle. Like myself, these users are not experts in the
> technical details of map projections, nor the problems of making pre-1936
> maps fit within today's UK Ordnance Survey OSGB36 Grid References.
> However, we need to know whether  anyone knows how to persuade QGIS/GDAL to
> locate these tiles in the correct place please?
>
> --------------------------------------------------
> PROBLEM PREVIOUSLY ADDRESSED TO GDAL FORUM:
>
> A friend, a relative newcomer to GIS, is having problems loading some of the
> TIFs created with Mapinfo into QGIS. Each TIF has a TAB file and in some
> cases the TAB file is interpreted correctly and in other cases the TAB file
> is (apparently) not recognised.
> I think this might be a problem with Gdal rather than a problem with QGIS.
> Taking just two of the TIFs, the output from gdalinfo when run on
> 33044061.TIF indicates that things are working as they should. However, when
> gdalinfo is run on 33044071.TIF the spatial data in its TAB file is not
> recognised. See the listings below.
>
> The strange thing is that all of the TIFs can successfully be converted from
> TIF to GeoTIFF using gdalwarp. (But it is important to my friend that he
> should be able to open Mapinfo raster images directly.)
>
> Any ideas?
>
> Regards,
> Nick.
>
>
> Contents of 33044061.TAB:
> ------------------------
> !table
> !version 300
> !charset WindowsLatin1
>
> Definition Table
>    File "33044061.tif"
>    Type "RASTER"
>    (582429,263569) (1,7594) Label "Pt 1",
>    (582372,265177) (1,0) Label "Pt 2",
>    (584784,265263) (11335,1) Label "Pt 3",
>    (584841,263655) (11335,7594) Label "Pt 4"
>    CoordSys Earth Projection 8, 79, "m", -2, 49, 0.9996012717, 400000,
> -100000
>    Units "m"
>
> Results of running gdalinfo on 33044061.TIF:
> -------------------------------------------
> nick@nick-6150M2MA:~/Desktop/tabstuff$ gdalinfo 33044061.TIF
> Warning 1: TIFFFetchNormalTag:ASCII value for tag "ImageDescription"
> contains null byte in value; value incorrectly truncated
> during reading due to implementation limitations
> Driver: GTiff/GeoTIFF
> Files: 33044061.TIF
> Size is 11335, 7594
> Coordinate System is:
> PROJCS["unnamed",
>      GEOGCS["unnamed",
>          DATUM["OSGB_1936",
>              SPHEROID["Airy 1930",6377563.396,299.3249646],
>              TOWGS84[375,-111,431,-0,-0,-0,0]],
>          PRIMEM["Greenwich",0],
>          UNIT["degree",0.0174532925199433]],
>      PROJECTION["Transverse_Mercator"],
>      PARAMETER["latitude_of_origin",49],
>      PARAMETER["central_meridian",-2],
>      PARAMETER["scale_factor",0.9996012717],
>      PARAMETER["false_easting",400000],
>      PARAMETER["false_northing",-100000],
>      UNIT["Meter",1]]
> GeoTransform =
>    582371.785312838, 0.2128106799708935, 0.007506419931892793
>    265177.0453393974, 0.007597130759524194, -0.2117600570261751
> Metadata:
>    TIFFTAG_IMAGEDESCRIPTION=
>    TIFFTAG_XRESOLUTION=300
>    TIFFTAG_YRESOLUTION=300
>    TIFFTAG_MINSAMPLEVALUE=0
>    TIFFTAG_MAXSAMPLEVALUE=1
>    TIFFTAG_RESOLUTIONUNIT=2 (pixels/inch)
> Image Structure Metadata:
>    COMPRESSION=CCITTFAX4
>    INTERLEAVE=BAND
>    MINISWHITE=YES
> Corner Coordinates:
> Upper Left  (  582371.785,  265177.045) (  0d40'19.83"E, 52d15'14.75"N)
> Lower Left  (  582428.789,  263568.939) (  0d40'19.71"E, 52d14'22.68"N)
> Upper Right (  584783.994,  265263.159) (  0d42'27.09"E, 52d15'14.63"N)
> Lower Right (  584840.998,  263655.053) (  0d42'26.92"E, 52d14'22.57"N)
> Center      (  583606.392,  264416.049) (  0d41'23.39"E, 52d14'48.66"N)
> Band 1 Block=512x512 Type=Byte, ColorInterp=Palette
>    Image Structure Metadata:
>      NBITS=1
>    Color Table (RGB with 2 entries)
>      0: 255,255,255,255
>      1: 0,0,0,255
> nick@nick-6150M2MA:~/Desktop/tabstuff$
>
> Contents of 33044071.TAB:
> ------------------------
> !table
> !version 300
> !charset WindowsLatin1
>
> Definition Table
>    File "33044071.tif"
>    Type "RASTER"
>    (584841,263655) (1,7576) Label "Pt 1",
>    (584784,265263) (1,0) Label "Pt 2",
>    (587197,265349) (11335,1) Label "Pt 3",
>    (587254,263740) (11335,7576) Label "Pt 4"
>    CoordSys Earth Projection 8, 79, "m", -2, 49, 0.9996012717, 400000,
> -100000
>    Units "m"
>
> Results of running gdalinfo on 33044071.TIF:
> -------------------------------------------
> nick@nick-6150M2MA:~/Desktop/tabstuff$ gdalinfo 33044071.TIF
> Warning 1: TIFFFetchNormalTag:ASCII value for tag "ImageDescription"
> contains null byte in value; value incorrectly truncated
> during reading due to implementation limitations
> Driver: GTiff/GeoTIFF
> Files: 33044071.TIF
> Size is 11335, 7576
> Coordinate System is `'
> GCP Projection =
> PROJCS["unnamed",
>      GEOGCS["unnamed",
>          DATUM["OSGB_1936",
>              SPHEROID["Airy 1930",6377563.396,299.3249646],
>              TOWGS84[375,-111,431,-0,-0,-0,0]],
>          PRIMEM["Greenwich",0],
>          UNIT["degree",0.0174532925199433]],
>      PROJECTION["Transverse_Mercator"],
>      PARAMETER["latitude_of_origin",49],
>      PARAMETER["central_meridian",-2],
>      PARAMETER["scale_factor",0.9996012717],
>      PARAMETER["false_easting",400000],
>      PARAMETER["false_northing",-100000],
>      UNIT["Meter",1]]
> GCP[  0]: Id=Pt 1, Info=
>            (1,7576) -> (584841,263655,0)
> GCP[  1]: Id=Pt 2, Info=
>            (1,0) -> (584784,265263,0)
> GCP[  2]: Id=Pt 3, Info=
>            (11335,1) -> (587197,265349,0)
> GCP[  3]: Id=Pt 4, Info=
>            (11335,7576) -> (587254,263740,0)
> Metadata:
>    TIFFTAG_IMAGEDESCRIPTION=
>    TIFFTAG_XRESOLUTION=300
>    TIFFTAG_YRESOLUTION=300
>    TIFFTAG_MINSAMPLEVALUE=0
>    TIFFTAG_MAXSAMPLEVALUE=1
>    TIFFTAG_RESOLUTIONUNIT=2 (pixels/inch)
> Image Structure Metadata:
>    COMPRESSION=CCITTFAX4
>    INTERLEAVE=BAND
>    MINISWHITE=YES
> Corner Coordinates:
> Upper Left  (    0.0,    0.0)
> Lower Left  (    0.0, 7576.0)
> Upper Right (11335.0,    0.0)
> Lower Right (11335.0, 7576.0)
> Center      ( 5667.5, 3788.0)
> Band 1 Block=512x512 Type=Byte, ColorInterp=Palette
>    Image Structure Metadata:
>      NBITS=1
>    Color Table (RGB with 2 entries)
>      0: 255,255,255,255
>      1: 0,0,0,255
> -------------------------------------------------------------------
>
>
> FRANK WARMERDAM REPLIED:
>
>
> Nick,
>
> I haven't tried the .TAB files locally, but I see they are both resulting in
> georeferencing info.  The one is expressed as a
>
> geotransform with rotation and shear while the other is expressed as ground
> control points.
>
> I believe that the .TAB reader attempts to compute a geotransform from the
> points in the TAB and if it can do so with minimal
>
> error then that is what is returned - a solution easier to utilize in QGIS
> and other applications.
>
> If the control points do not represent a clean affine transformation for the
> image then it falls back to returning them as
>
> ground control points which relatively few applications can utilize
> directly.
>
> One "solution" is to run gdalwarp to transform the image that isn't
> currently working so well into a north up affine
>
> transformation style image.
>   eg.
>
> gdalwarp 33044071.TIF 33044071_northup.TIF
>
> This warp will be done using the control points (ironically also using a
> best fit first order polynomial).
>
> The code responsible for the decision is this from gdal/gcore/gdal_misc.cpp:
>
>
> /* -------------------------------------------------------------------- */
>
> /*      Try to convert the GCPs into a geotransform definition, if      */
>
> /*      possible.  Otherwise we will need to use them as GCPs.          */
>
> /* -------------------------------------------------------------------- */
>
>      if( !GDALGCPsToGeoTransform( nCoordinateCount, asGCPs, padfGeoTransform,
>
>                                   FALSE ) )
>
>      {
>
>          if (pnGCPCount && ppasGCPs)
>
>          {
>
>              CPLDebug( "GDAL",
>
>                  "GDALLoadTabFile(%s) found file, wasn't able to derive a\n"
>
>                  "first order geotransform.  Using points as GCPs.",
>
>                  pszFilename );
>
>
>
>
>              *ppasGCPs = (GDAL_GCP *)
>
>                  CPLCalloc( sizeof(GDAL_GCP),nCoordinateCount );
>
>              memcpy( *ppasGCPs, asGCPs, sizeof(GDAL_GCP) * nCoordinateCount
> );
>
>              *pnGCPCount = nCoordinateCount;
>
>          }
>
>      }
>
>      else
>
>      {
>
>          GDALDeinitGCPs( nCoordinateCount, asGCPs );
>
>      }
>
>   I suspect if you change the FALSE to TRUE in the arguments to
> GDALGCPsToGeoTransform() you wlil always get an affine
>
> transform even when it is not a very good fit.
>
>
>
> --
> View this message in context: http://osgeo-org.1560.x6.nabble.com/Problem-correctly-reading-Mapinfo-TIF-and-TAB-files-into-QGIS-tp5095647.html
> Sent from the Quantum GIS - User mailing list archive at Nabble.com.
> _______________________________________________
> Qgis-user mailing list
> [hidden email]
> http://lists.osgeo.org/mailman/listinfo/qgis-user

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33044061.TAB (422 bytes) Download Attachment
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33044071.TIF (1M) Download Attachment
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Re: Problem correctly reading Mapinfo TIF and TAB files into QGIS

Jonathan Moules-2
Hi David,
We've merged our Historical maps together into a single raster for each historical map, you might want to try that - it's much easier dealing with a single file than thousands of little ones.

Alternately as noted you could use a virtual raster, but I found that mosaicing all of our Historical Maps together was the optimal solution (in our case into GeoTiffs).

Or you may wish to re-ask for your data from Landmark (I'm assuming that's where it's from) - we got a re-supply a year ago at no cost to us (we'd already paid after all) which was of much better quality than the original files we got in ~2004.
Regards,
Jonathan



On 28 December 2013 12:48, David Addy <[hidden email]> wrote:

Hi Bo Victor,

Thanks for your reply to my enquiry. The two files referred to in the discussion are attached.

I hope that this helps you.

I do not know how to make these generally available to the whole  QGIS list, so I am  sending them to you off list.

Best wishes,

David

 

David Addy

10 Northgate Avenue

Bury St Edmunds

Suffolk

IP32 6BB

 

Telephone 01284 704247

Mobile      07766 178 459

 

Are you interested in the local history of West Suffolk? If so, try my local history site at:-

http://www.stedmundsburychronicle.com/index.htm

 

And including new for 2014, a picture gallery of  our area during the Great War, 1914-1919

http://www.stedmundsburychronicle.com/galleryww1/galleryww1home.htm

 

 

 

From: Bo Victor Thomsen [via OSGeo.org] [mailto:[hidden email]]
Sent: 28 December 2013 09:33
To: David Addy
Subject: Re: Problem correctly reading Mapinfo TIF and TAB files into QGIS

 

Nick -

Could you make a couple of "problem" and "no problem" tiff/tab files
available ?

Regards
Bo Victor Thomsen
Aestas-GIS
Denamrk

Den 27-12-2013 19:31, David Addy skrev:


> In this area of the UK, a number of local authorities use Mapinfo for their
> Archaeology and Record Office services. This often involves reading
> historical maps in order to compare with current conditions on the ground.
> All such maps are calibrated within Mapinfo, and are usually in the form of
> .TIF files accompanied by a .TAB file giving the georeferencing data. As
> these departments are constantly under budgetary pressure there are many
> applications where the use of QGIS could result in considerable cost
> savings. However, it is necessary that existing maps should be easily read
> by QGIS and correctly located,
> without a cumbersome file conversion process.
> An example of such maps is the 1880s First Series 1:2500 scale county
> Ordnance Survey maps for Suffolk. At this scale it takes a large number of
> tiles to cover a whole county. In a sample dozen of such maps around Bury St
> Edmunds, only four were correctly located by QGIS. My mapping friend Nick
> Hopton has kindly addressed this problem to the GDAL forum, using two sample
> tiles, one of which works in QGIS and the other does not. The discussion on
> this is reproduced below, and appears to come down to the size of the error
> found by GDAL in its attempted transformation. AS this error seems to be
> acceptable within Mapinfo, I do not quite understand why it cannot work
> equally well within QGIS.
> Obviously this must be a critical issue for all Mapinfo users who would like
> to adopt QGIS, but find that this problem causes their evaluations to fail
> at the first hurdle. Like myself, these users are not experts in the
> technical details of map projections, nor the problems of making pre-1936
> maps fit within today's UK Ordnance Survey OSGB36 Grid References.
> However, we need to know whether  anyone knows how to persuade QGIS/GDAL to
> locate these tiles in the correct place please?
>
> --------------------------------------------------
> PROBLEM PREVIOUSLY ADDRESSED TO GDAL FORUM:
>
> A friend, a relative newcomer to GIS, is having problems loading some of the
> TIFs created with Mapinfo into QGIS. Each TIF has a TAB file and in some
> cases the TAB file is interpreted correctly and in other cases the TAB file
> is (apparently) not recognised.
> I think this might be a problem with Gdal rather than a problem with QGIS.
> Taking just two of the TIFs, the output from gdalinfo when run on
> 33044061.TIF indicates that things are working as they should. However, when
> gdalinfo is run on 33044071.TIF the spatial data in its TAB file is not
> recognised. See the listings below.
>
> The strange thing is that all of the TIFs can successfully be converted from
> TIF to GeoTIFF using gdalwarp. (But it is important to my friend that he
> should be able to open Mapinfo raster images directly.)
>
> Any ideas?
>
> Regards,
> Nick.
>
>
> Contents of 33044061.TAB:
> ------------------------
> !table
> !version 300
> !charset WindowsLatin1
>
> Definition Table
>    File "33044061.tif"
>    Type "RASTER"
>    (582429,263569) (1,7594) Label "Pt 1",
>    (582372,265177) (1,0) Label "Pt 2",
>    (584784,265263) (11335,1) Label "Pt 3",
>    (584841,263655) (11335,7594) Label "Pt 4"
>    CoordSys Earth Projection 8, 79, "m", -2, 49, 0.9996012717, 400000,
> -100000
>    Units "m"
>
> Results of running gdalinfo on 33044061.TIF:
> -------------------------------------------
> nick@nick-6150M2MA:~/Desktop/tabstuff$ gdalinfo 33044061.TIF
> Warning 1: TIFFFetchNormalTag:ASCII value for tag "ImageDescription"
> contains null byte in value; value incorrectly truncated
> during reading due to implementation limitations
> Driver: GTiff/GeoTIFF
> Files: 33044061.TIF
> Size is 11335, 7594
> Coordinate System is:
> PROJCS["unnamed",
>      GEOGCS["unnamed",
>          DATUM["OSGB_1936",
>              SPHEROID["Airy 1930",6377563.396,299.3249646],
>              TOWGS84[375,-111,431,-0,-0,-0,0]],
>          PRIMEM["Greenwich",0],
>          UNIT["degree",0.0174532925199433]],
>      PROJECTION["Transverse_Mercator"],
>      PARAMETER["latitude_of_origin",49],
>      PARAMETER["central_meridian",-2],
>      PARAMETER["scale_factor",0.9996012717],
>      PARAMETER["false_easting",400000],
>      PARAMETER["false_northing",-100000],
>      UNIT["Meter",1]]
> GeoTransform =
>    582371.785312838, 0.2128106799708935, 0.007506419931892793
>    265177.0453393974, 0.007597130759524194, -0.2117600570261751
> Metadata:
>    TIFFTAG_IMAGEDESCRIPTION=
>    TIFFTAG_XRESOLUTION=300
>    TIFFTAG_YRESOLUTION=300
>    TIFFTAG_MINSAMPLEVALUE=0
>    TIFFTAG_MAXSAMPLEVALUE=1
>    TIFFTAG_RESOLUTIONUNIT=2 (pixels/inch)
> Image Structure Metadata:
>    COMPRESSION=CCITTFAX4
>    INTERLEAVE=BAND
>    MINISWHITE=YES
> Corner Coordinates:
> Upper Left  (  582371.785,  265177.045) (  0d40'19.83"E, 52d15'14.75"N)
> Lower Left  (  582428.789,  263568.939) (  0d40'19.71"E, 52d14'22.68"N)
> Upper Right (  584783.994,  265263.159) (  0d42'27.09"E, 52d15'14.63"N)
> Lower Right (  584840.998,  263655.053) (  0d42'26.92"E, 52d14'22.57"N)
> Center      (  583606.392,  264416.049) (  0d41'23.39"E, 52d14'48.66"N)
> Band 1 Block=512x512 Type=Byte, ColorInterp=Palette
>    Image Structure Metadata:
>      NBITS=1
>    Color Table (RGB with 2 entries)
>      0: 255,255,255,255
>      1: 0,0,0,255
> nick@nick-6150M2MA:~/Desktop/tabstuff$
>
> Contents of 33044071.TAB:
> ------------------------
> !table
> !version 300
> !charset WindowsLatin1
>
> Definition Table
>    File "33044071.tif"
>    Type "RASTER"
>    (584841,263655) (1,7576) Label "Pt 1",
>    (584784,265263) (1,0) Label "Pt 2",
>    (587197,265349) (11335,1) Label "Pt 3",
>    (587254,263740) (11335,7576) Label "Pt 4"
>    CoordSys Earth Projection 8, 79, "m", -2, 49, 0.9996012717, 400000,
> -100000
>    Units "m"
>
> Results of running gdalinfo on 33044071.TIF:
> -------------------------------------------
> nick@nick-6150M2MA:~/Desktop/tabstuff$ gdalinfo 33044071.TIF
> Warning 1: TIFFFetchNormalTag:ASCII value for tag "ImageDescription"
> contains null byte in value; value incorrectly truncated
> during reading due to implementation limitations
> Driver: GTiff/GeoTIFF
> Files: 33044071.TIF
> Size is 11335, 7576
> Coordinate System is `'
> GCP Projection =
> PROJCS["unnamed",
>      GEOGCS["unnamed",
>          DATUM["OSGB_1936",
>              SPHEROID["Airy 1930",6377563.396,299.3249646],
>              TOWGS84[375,-111,431,-0,-0,-0,0]],
>          PRIMEM["Greenwich",0],
>          UNIT["degree",0.0174532925199433]],
>      PROJECTION["Transverse_Mercator"],
>      PARAMETER["latitude_of_origin",49],
>      PARAMETER["central_meridian",-2],
>      PARAMETER["scale_factor",0.9996012717],
>      PARAMETER["false_easting",400000],
>      PARAMETER["false_northing",-100000],
>      UNIT["Meter",1]]
> GCP[  0]: Id=Pt 1, Info=
>            (1,7576) -> (584841,263655,0)
> GCP[  1]: Id=Pt 2, Info=
>            (1,0) -> (584784,265263,0)
> GCP[  2]: Id=Pt 3, Info=
>            (11335,1) -> (587197,265349,0)
> GCP[  3]: Id=Pt 4, Info=
>            (11335,7576) -> (587254,263740,0)
> Metadata:
>    TIFFTAG_IMAGEDESCRIPTION=
>    TIFFTAG_XRESOLUTION=300
>    TIFFTAG_YRESOLUTION=300
>    TIFFTAG_MINSAMPLEVALUE=0
>    TIFFTAG_MAXSAMPLEVALUE=1
>    TIFFTAG_RESOLUTIONUNIT=2 (pixels/inch)
> Image Structure Metadata:
>    COMPRESSION=CCITTFAX4
>    INTERLEAVE=BAND
>    MINISWHITE=YES
> Corner Coordinates:
> Upper Left  (    0.0,    0.0)
> Lower Left  (    0.0, 7576.0)
> Upper Right (11335.0,    0.0)
> Lower Right (11335.0, 7576.0)
> Center      ( 5667.5, 3788.0)
> Band 1 Block=512x512 Type=Byte, ColorInterp=Palette
>    Image Structure Metadata:
>      NBITS=1
>    Color Table (RGB with 2 entries)
>      0: 255,255,255,255
>      1: 0,0,0,255
> -------------------------------------------------------------------
>
>
> FRANK WARMERDAM REPLIED:
>
>
> Nick,
>
> I haven't tried the .TAB files locally, but I see they are both resulting in
> georeferencing info.  The one is expressed as a
>
> geotransform with rotation and shear while the other is expressed as ground
> control points.
>
> I believe that the .TAB reader attempts to compute a geotransform from the
> points in the TAB and if it can do so with minimal
>
> error then that is what is returned - a solution easier to utilize in QGIS
> and other applications.
>
> If the control points do not represent a clean affine transformation for the
> image then it falls back to returning them as
>
> ground control points which relatively few applications can utilize
> directly.
>
> One "solution" is to run gdalwarp to transform the image that isn't
> currently working so well into a north up affine
>
> transformation style image.
>   eg.
>
> gdalwarp 33044071.TIF 33044071_northup.TIF
>
> This warp will be done using the control points (ironically also using a
> best fit first order polynomial).
>
> The code responsible for the decision is this from gdal/gcore/gdal_misc.cpp:
>
>
> /* -------------------------------------------------------------------- */
>
> /*      Try to convert the GCPs into a geotransform definition, if      */
>
> /*      possible.  Otherwise we will need to use them as GCPs.          */
>
> /* -------------------------------------------------------------------- */
>
>      if( !GDALGCPsToGeoTransform( nCoordinateCount, asGCPs, padfGeoTransform,
>
>                                   FALSE ) )
>
>      {
>
>          if (pnGCPCount && ppasGCPs)
>
>          {
>
>              CPLDebug( "GDAL",
>
>                  "GDALLoadTabFile(%s) found file, wasn't able to derive a\n"
>
>                  "first order geotransform.  Using points as GCPs.",
>
>                  pszFilename );
>
>
>
>
>              *ppasGCPs = (GDAL_GCP *)
>
>                  CPLCalloc( sizeof(GDAL_GCP),nCoordinateCount );
>
>              memcpy( *ppasGCPs, asGCPs, sizeof(GDAL_GCP) * nCoordinateCount
> );
>
>              *pnGCPCount = nCoordinateCount;
>
>          }
>
>      }
>
>      else
>
>      {
>
>          GDALDeinitGCPs( nCoordinateCount, asGCPs );
>
>      }
>
>   I suspect if you change the FALSE to TRUE in the arguments to
> GDALGCPsToGeoTransform() you wlil always get an affine
>
> transform even when it is not a very good fit.
>
>
>
> --
> View this message in context: http://osgeo-org.1560.x6.nabble.com/Problem-correctly-reading-Mapinfo-TIF-and-TAB-files-into-QGIS-tp5095647.html
> Sent from the Quantum GIS - User mailing list archive at Nabble.com.
> _______________________________________________
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33044061.TAB (422 bytes) Download Attachment
33044061.TIF (591K) Download Attachment
33044071.TAB (422 bytes) Download Attachment
33044071.TIF (1M) Download Attachment


View this message in context: RE: Problem correctly reading Mapinfo TIF and TAB files into QGIS

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