2004.09.14 13:50 "[Tiff] Removing reduced resolution pages", by Han The Man

2004.09.14 13:50 "[Tiff] Removing reduced resolution pages", by Han The Man

Hi all,

I have about 50.000 TIFF files, some of them having pages with "reduced-resolution" pages.

I want to remove any pages in those TIFF files marked as reduced-resolution. So in essence, I want to replace the original file with a new file not having reduced-resolution pages.

Can I do that reliably using libtiff?

Below is a sample output from TIFFINFO. I know (by visual inspection) that the reduced resolution images are at page 2 and 4.

The subfiletype is 0x03 for page 2 and 4, but according to the TIFF 6.0 spec about "Subfiletype", 0x03 means "a single page of a multipage image".

Shouldn't TIFFINFO print 0x02 - "reduced-resolution image".

What am I missing?

Also, how can I best remove reduced-resolution pages from my TIFF files?

Best,
Han

------ TIFFINFO OUTPUT ---

TIFF Directory at offset 0x8
  Subfile Type: multi-page document (2 = 0x2)
  Image Width: 2472 Image Length: 3504
  Tile Width: 512 Tile Length: 512
  Resolution: 300, 300 pixels/inch
  Bits/Sample: 1
  Compression Scheme: CCITT Group 4
  Photometric Interpretation: min-is-white
  FillOrder: msb-to-lsb
  Date & Time: "2002:11:11 11:11:11"
  Image Description: "(removed)"
  Make: "(removed)"
  Model: "(removed)"
  Orientation: row 0 top, col 0 lhs
  Samples/Pixel: 1
  Planar Configuration: single image plane
  Software: (removed)
  Tag 34860: (removed)
  Group 4 Options: (0 = 0x0)

TIFF Directory at offset 0x9cec
  Subfile Type: reduced-resolution image/multi-page document (3 = 0x3)
  Image Width: 618 Image Length: 876
  Tile Width: 512 Tile Length: 512
  Resolution: 75, 75 pixels/inch
  Bits/Sample: 1
  Compression Scheme: CCITT Group 4
  Photometric Interpretation: min-is-white
  FillOrder: msb-to-lsb
  Orientation: row 0 top, col 0 lhs
  Samples/Pixel: 1
  Planar Configuration: single image plane
  Group 4 Options: (0 = 0x0)

TIFF Directory at offset 0xc2e4
  Subfile Type: multi-page document (2 = 0x2)
  Image Width: 2472 Image Length: 3504
  Tile Width: 512 Tile Length: 512
  Resolution: 300, 300 pixels/inch
  Bits/Sample: 1
  Compression Scheme: CCITT Group 4
  Photometric Interpretation: min-is-white
  FillOrder: msb-to-lsb
  Date & Time: "2002:11:11 11:11:11"
  Image Description: "(removed)"
  Make: "(removed)"
  Model: "(removed)"
  Orientation: row 0 top, col 0 lhs
  Samples/Pixel: 1
  Planar Configuration: single image plane
  Software: (removed)
  Tag 34860: (removed)
  Group 4 Options: (0 = 0x0)

TIFF Directory at offset 0x11cc0
  Subfile Type: reduced-resolution image/multi-page document (3 = 0x3)
  Image Width: 618 Image Length: 876
  Tile Width: 512 Tile Length: 512
  Resolution: 75, 75 pixels/inch
  Bits/Sample: 1
  Compression Scheme: CCITT Group 4
  Photometric Interpretation: min-is-white
  FillOrder: msb-to-lsb
  Orientation: row 0 top, col 0 lhs
  Samples/Pixel: 1
  Planar Configuration: single image plane
  Group 4 Options: (0 = 0x0)