2008.02.11 07:43 "[Tiff] TIFFReadRGBAImage rendering upside-down", by Mick O'Neill

2008.02.12 02:31 "Re: [Tiff] Re: Help with TIFFWriteScanline()", by James Sumners

Indeed I was. I thought I had sent a couple follow ups to the list where I said I figured that out. Maybe they didn't come through?

On Feb 11, 2008 12:20 PM, Chris Cox <ccox@adobe.com> wrote:

I think you're confusing SamplesPerPixel with BitsPerSample.

-----Original Message-----

From: tiff-bounces@lists.maptools.org on behalf of James Sumners Sent: Mon 2/11/2008 8:33 AM

To: tiff@lists.maptools.org

Subject: [Tiff] Re: Help with TIFFWriteScanline()

After browsing the mailing list archives I found out about the tiffinfo tool. tiffinfo reported that my original image had a SamplesPerPixel of 1. For some reason, unbeknownst to me, my program is getting a value of 0 for SamplesPerPixel from the original image. So I manually set the value to 8, because that is what I understand the specification to be (8 or 16 SPP for grayscale/color and 1 SPP for bilevel). After changing my manual SPP value from 8 to 1 the copied image is written correctly.

This is the first time I've done any graphics programming. So I'm sure that I am not understanding something. Would someone please explain this situation to me? Would 8 SPP squeeze the image into a smaller space? How is 1 SPP producing a grayscale image?

James Sumners

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