geotiff-fortran

Minimalistic Fortran GeoTIFF module, with sintax inspired on LIBTIFF C-Library.

List of functions available

Open/close file:

• TIFF_Open (iunit, fileName, 'r', tiff, ierror)
• TIFF_Close (tiff)

Read commands:

• TIFF_Get_Tag_Value (tiff, tagId, value)
• TIFF_Get_Image (tiff, *nimg, image)
• GTIFF_Get_Key_Value(tiff, keyId, value)
• GTIFF_Get_Image_Coordinates(tiff, *nimg*, x, y)

Write commands:

• TIFF_Set_Tag_Value (tiff, tagId, value)
• TIFF_Set_Image (tiff, *nimg, image)
• GTIFF_Set_Key_Value(tiff, keyId, value)
• TIFF_Write_TIFF(tiff)

Example of use

program my_program

   use geoTIFF

   implicit none  
   type(TIFF_FILE) :: my_tiff
   integer              :: ierr,crs
   character(100)       :: descr
   real   , allocatable :: image(:,:),x(:,:),y(:,:)
   
   call TIFF_Open(124,"files/cea.tif",'r', my_tiff, ierr)
   if (ierr==0) then
   
      !get TIFF tag:
      call TIFF_GET_TAG_VALUE(my_tiff, 1, TIFF_ImageDescription, descr)
   
      !get TIFF image:
      allocate(image(my_tiff%nx, my_tiff%ny))
      call TIFF_GET_IMAGE(my_tiff, 1, image)

      !get GeoTIFF key:
      call GTIFF_GET_KEY_VALUE(my_tiff, GKEY_ProjectedCSType, crs)

      !get coordinates
      allocate(x(my_tiff%nx, my_tiff%ny))
      allocate(y(my_tiff%nx, my_tiff%ny))
      call GTIFF_GET_IMAGE_COORDINATES(my_tiff,1,x,y)

      call TIFF_Close(my_tiff)
   else
      stop 'Failed to read TIFF file'
   endif

end program

To-do list:

General:

• Read/Open function implementation
• Write/Create function implementation
• IO-error management

TIFF 6.0 Baseline:

• Big-Enddian support (swap byte-order)
• Orientation: different orientation images (not all tested)
• Compression: PackBits
• Compression: Modified Huffman (CCITT Group 3,1-D) (only for bilevel data)
• Multi-image TIFF (more than 1 IFD)
• Multiband TIFFs
• Planar configuration TIFFs
• Extend TIFF_Get_Image for categorical (integer) layers

TIFF 6.0 Extensions:

• Tiled images
• Compression: LZW
• Compression: DEFLATE (LZ77 + Huffman)
• Differencing predictor algorithm
• Data Sample Format

OGC GEOTIFF 1.1

• GeoKey values access
• Find how to get coordinates info
• Get proj code (epsg or projstring)

Performance:

• Memory (RSS)
• CPU usage testing
• Parallel access? (is it possible?)