AWARE SYSTEMS
TIFF and LibTiff Mail List Archive

Thread

2008.03.29 04:18 "[Tiff] TIFFReadRawStrip buffer data type", by James Sumners
2008.03.29 06:05 "Re: [Tiff] TIFFReadRawStrip buffer data type", by Bob Friesenhahn
2008.03.29 11:44 "Re: [Tiff] TIFFReadRawStrip buffer data type", by James Sumners
2008.03.29 15:41 "Re: [Tiff] TIFFReadRawStrip buffer data type", by Bob Friesenhahn
2008.03.29 16:26 "Re: [Tiff] TIFFReadRawStrip buffer data type", by James Sumners
2008.03.29 14:58 "Re: [Tiff] TIFFReadRawStrip buffer data type", by Frank Warmerdam
2008.03.29 16:29 "Re: [Tiff] TIFFReadRawStrip buffer data type", by James Sumners
2008.03.29 16:51 "Re: [Tiff] TIFFReadRawStrip buffer data type", by Bob Friesenhahn
2008.04.24 14:16 "Re: [Tiff] TIFFReadRawStrip buffer data type", by James Sumners

2008.03.29 16:26 "Re: [Tiff] TIFFReadRawStrip buffer data type", by James Sumners

This is the specifications on the image as my program sees it:

Input image specifications:

512x512  photo = 1       8bpp    1spp    order = 0

res_unit = 2    xres = 72.000000        yres = 72.000000

compression: 1

rows per strip: 64      strips: 8       bytes per strip: 32768

And as the tiffinfo utility sees it:

TIFF Directory at offset 0x40008 (262152)
    Subfile Type: (0 = 0x0)
    Image Width: 512 Image Length: 512
    Resolution: 72, 72 pixels/inch
    Bits/Sample: 8
    Compression Scheme: None
    Photometric Interpretation: min-is-black
    Orientation: row 0 top, col 0 lhs
    Samples/Pixel: 1
    Rows/Strip: 64
    Planar Configuration: single image plane

So it looks like I am working with the data under the optimal conditions you specify.

On Sat, Mar 29, 2008 at 11:41 AM, Bob Friesenhahn <bfriesen@simple.dallas.tx.us> wrote:

Well, the image I'm reading is not compressed. So I thought the data would just be the integer color value of each pixel. If that is incorrect, how would I get that data? I want to be able to work with the color values for the pixels so that I can do my own compression.

If the image is not compressed, then you should be ok. What is the bits-per-sample of your data? If it is 8 and you are using the RGB photometric with three samples per pixel, then each byte would be one sample representing R, G, or B. If bits-per-sample is 1, 2, or 4 then there is much more work to do since multiple samples will be packed in a byte.

--
James Sumners
http://james.roomfullofmirrors.com/

"All governments suffer a recurring problem: Power attracts
pathological personalities. It is not that power corrupts but that it
is magnetic to the corruptible. Such people have a tendency to become
drunk on violence, a condition to which they are quickly addicted."

Missionaria Protectiva, Text QIV (decto)
CH:D 59