int  ( __stdcall *pfnFFTiffServices )( int, HANDLE, void*, int, int );

• read file services:
  • service 1 - check TIFF signature
  • service 2 - get image width in pixels
  • service 3 - get image length in lines
  • service 4 - get the image comment (max 1024 bytes)
  • service 5 - position file pointer to the beginning of the compressed data
• create file services:
  • service 6 - create and start writing a new TIFF file
  • service 7 - stop writing and close a new TIFF file

When reading a file, also, please call services 1, 2, 3, 4 and 5 in ascending sequence and don't miss any of them, differently an error could be returned.

An optional tag in the TIFF specification is used to record information about the image stored in the TIFF file. This tag is the ImageDescription tag. Since the beginning I had the idea to use this tag to record the database keys of the stored image.

For this reason I implemented the comment feature to read or write the database keys (or some other useful information) into the ImageDescription tag. You can write a comment (i.e. the database keys) using parameter 3 of service 6, and you can read the comment using the return value of service 4.

Using the image comment feature to store the image description (and/or the database keys) together with the images themselves is a very good way for developing robust applications.

• first parameter: number of the requested service (from 1 to 7)
• second parameter:
  • services 1, 4, 5, 7: TIFF file handle (you should open the file)
  • service 6: pointer to the ASCIIZ file name of the TIFF file to be created
  • services 2, 3: NULL
• third parameter:
  • service 6: pointer to the ASCIIZ image comment string for the TIFF file to be created
  • services 1, 2, 3, 4, 5, 7: NULL
• fourth parameter:
  • service 6: image width in pixels
  • services 1, 2, 3, 4, 5, 7: NULL
• fifth parameter:
  • service 6: image length in lines
  • services 1, 2, 3, 4, 5, 7: NULL

• service 1: 0=the file is TIFF; 1=the file is not TIFF
• service 2: image width in pixels
• service 3: image length in lines
• service 4: pointer to the ASCIIZ string with the image comment
• service 5: 1=correctly positioned; anything else=error
• service 6: handle to the newly created file (0=not created)
• service 7: 1=correctly closed; anything else=error