2003.11.17 17:25 "[Tiff] reading Affymetrix tiff images", by Frank Warmerdam

I am trying to read affymetrix tiff images. As you said before I printed the tiffinfo. It gave like this:

sample.tif: Warning, invalid TIFF directory; tags are not sorted in ascending order.
sample.tif: Warning, TIFF directory is missing required "StripByteCounts" field, calculating from imagelength.
TIFF Directory at offset 0x8
  Image Width: 4733 Image Length: 4733
  Bits/Sample: 8
  Compression Scheme: None
  Photometric Interpretation: min-is-black
  Image Description: "[30..46140] PGA-HCL-astM_atop-10aUA-s2:CLS=4733 RWS=4733 XIN=3 YIN=3 VE=17 2.0 09/04/02 15:32:34 \024 \024 HG-U133A.1sq \024 \024 \024 \024 \024 \024 \024 \024 \024 6"
  Planar Configuration: single image plane

my tiff image is sample.tif. from the above I understood that my tiff image doesn't use any compression. It also says single image plane. In the above output what does XIN and YIN and VE mean? Now can you explain me with a program(if possible) how to read the image data? one more doubt is in the above output where should i look for the type of image like is it scanline-based or strip based or tile based?

Sridhar,

You asked if this is a stripped or tiled image. The answer is it doesn't include any information on strips so I imagine this means the image is implicitly one big strip. In fact, the image seems pretty poorly populated and missing required fields. Presumably the image has 1 sample per pixel. The values in the Image Description are specific to the generating application, and not a general TIFF thing. You might need to talk to the Affymetrix people to find out more.

Best regards,

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