Thread

2000.02.03 20:17 "Simple question that became complex (long message)", by Thom Farrell

2000.02.03 20:53 "Re: Simple question that became complex (long message)", by Helge Blischke

2000.02.03 20:17 "Simple question that became complex (long message)", by Thom Farrell

Hi!

We have a Solaris 2.6 system with libtiff that we compiled from source in October of last year, sorry I don't have the version number off hand. In the system we have images from two sources; images we scan locally and images that we receive on magnetic tape from another agency. I have written a application which retrieves Group 4 TIFF images from the database (Informix 7.32UC2) and prints them via Vividata's PostShop 4.0 which makes use of Aladdin Ghostscrip 5.50. The images that were created locally seem to print OK but the images we receive from outside our agency print as thumbnails. After extracting a couple of the images and running tiffinfo on them I go some results that seem rather curious to me. Unfortunately I have not been able to figure out if it means what I think it means, hence this email.

This is the output for an image which prints OK:

TIFF Directory at offset 0x8
    Subfile Type: (0 = 0x0)
    Image Width: 2544 Image Length: 3296
    Resolution: 300, 300 pixels/inch
    Bits/Sample: 1
    Compression Scheme: CCITT Group 4
    Photometric Interpretation: min-is-white
    Thresholding: bilevel art scan
    FillOrder: lsb-to-msb
    Samples/Pixel: 1
    Rows/Strip: 3296
    Planar Configuration: single image plane
    Group 4 Options: (0 = 0x0)

This image prints as a thumbnail:

TIFF Directory at offset 0x8
    Image Width: 2544 Image Length: 3297
    Resolution: 6.27216e+07, 6.27216e+07
    Compression Scheme: CCITT Group 4 facsimile encoding
    Photometric Interpretation: min-is-white
    FillOrder: msb-to-lsb
    Orientation: row 0 top, col 0 lhs
    Planar Configuration: single image plane
    Group 4 Options: (0 = 0x0)

I don't really think it is a thumbnail but that is what it appears to be when I print it. The report on the Resolution line for the "thumbnail" concerns me. Is there something wrong with the image or is there a bug which is presenting the odd numbers in the "thumbnail"? Why is there no Subfile type, Thresholding, samples/pixel, and Rows/Strip on the "thumbnail"? Does this have to do with the different compression schemes?

If anyone can provide any information about this I would appreciate it; even it is read book "X". Thanks.

Thom