Thread: Bitunwise

Oh right. I fixed that ... it's a " " instead of a "". But I still am getting the wrong answer... every line is outputting the same thing. It's also outputting more than 20 (the image's width) pixel values.

if I had more time I would read the tiff specs and help you out. I can pretty much guarantee that the bit reading code is correct, I can not guarantee that what you're reading is right because I don't know the format and dont' have the time. It seems to be well documented though.

The problem is, I've read through the documentation and it doesn't really help out in how to display the bitwise images, unfortunately. I've read from http://libtiff.org . Do you have a better site/documentation for programming with the TIFF library?

I would look at Wotsit.org as hk_mp5kpdw suggested. At first glance, tiff doesn't really look that horrible. but it is just a quick glance. The library you're working with though may not be so well documented.

Maybe this will help. Here is a hex dump of your file.

Code:

49 49 2A 00 8A 00 00 00 58 02 00 00 01 00 00 00 58 02 00 00 
01 00 00 00 38 00 00 00 4B 00 00 00 67 00 00 00 80 00 00 00 
13 00 00 00 1C 00 00 00 19 00 00 00 09 00 00 00 80 3F DF EF 
08 14 12 07 05 84 40 DE 43 F7 83 82 19 01 00 80 38 47 4D 07 
00 CD E0 E8 5B BC 1C 8B D8 20 FD E0 E0 13 1C 1C 10 E7 00 DD 
E1 01 00 80 3A 07 EF 07 04 0E 0A F0 71 41 85 2D 07 FB 8D 60 
EF 5F 9C 1F EF F7 84 04 80 3F DF EF 08 13 C2 02 00 00 0D 00 
FE 00 04 00 01 00 00 00 00 00 00 00 00 01 03 00 01 00 00 00 
14 00 00 00 01 01 03 00 01 00 00 00 1A 00 00 00 02 01 03 00 
01 00 00 00 01 00 00 00 03 01 03 00 01 00 00 00 05 00 00 00 
06 01 03 00 01 00 00 00 01 00 00 00 11 01 04 00 04 00 00 00 
18 00 00 00 15 01 03 00 01 00 00 00 01 00 00 00 16 01 04 00 
01 00 00 00 08 00 00 00 17 01 04 00 04 00 00 00 28 00 00 00 
1A 01 05 00 01 00 00 00 08 00 00 00 1B 01 05 00 01 00 00 00 
10 00 00 00 28 01 03 00 01 00 00 00 02 00 00 00 00 00 00 00

So does that mean my file ISN'T just black and white bitonal?

Well if each byte (8 bits) represents a pixel (0 for black, and 255 for white), then no.

But if each bit represents a pixel, then it could still be.

Or a third possibility is the data is compressed.

The tif's file size is 300 bytes. I opened the tif and it is black and white (600x600). So a pixel must be one bit.

You said the tif's width is 20. When I opened it, it was 600.

Your program may be outputting the correct data. The tif's is just bigger than you thought. Somewhere in the tif header it may tell the width and height of the image.

from what I can tell:
- the blue is a signature
- green is offset to first "Image File Directory" (from spec)
- the red is the width and height
edit: red is resolution apparently

Code:

49 49 2A 00 8A 00 00 00 58 02 00 00 01 00 00 00 58 02 00 00 
01 00 00 00 38 00 00 00 4B 00 00 00 67 00 00 00 80 00 00 00 
13 00 00 00 1C 00 00 00 19 00 00 00 09 00 00 00 80 3F DF EF 
08 14 12 07 05 84 40 DE 43 F7 83 82 19 01 00 80 38 47 4D 07 
00 CD E0 E8 5B BC 1C 8B D8 20 FD E0 E0 13 1C 1C 10 E7 00 DD 
E1 01 00 80 3A 07 EF 07 04 0E 0A F0 71 41 85 2D 07 FB 8D 60 
EF 5F 9C 1F EF F7 84 04 80 3F DF EF 08 13 C2 02 00 00 0D 00 
FE 00 04 00 01 00 00 00 00 00 00 00 00 01 03 00 01 00 00 00 
14 00 00 00 01 01 03 00 01 00 00 00 1A 00 00 00 02 01 03 00 
01 00 00 00 01 00 00 00 03 01 03 00 01 00 00 00 05 00 00 00 
06 01 03 00 01 00 00 00 01 00 00 00 11 01 04 00 04 00 00 00 
18 00 00 00 15 01 03 00 01 00 00 00 01 00 00 00 16 01 04 00 
01 00 00 00 08 00 00 00 17 01 04 00 04 00 00 00 28 00 00 00 
1A 01 05 00 01 00 00 00 08 00 00 00 1B 01 05 00 01 00 00 00 
10 00 00 00 28 01 03 00 01 00 00 00 02 00 00 00 00 00 00 00

The resolution tag says it's 600x600, but the image width/height is 20x26. Or does it appear differently for you?

Azmeos, I was only working off of what swoopy said. You're right. 20x26 can be found here in red:

Code:

49 49 2A 00 8A 00 00 00 58 02 00 00 01 00 00 00 58 02 00 00
01 00 00 00 38 00 00 00 4B 00 00 00 67 00 00 00 80 00 00 00 
13 00 00 00 1C 00 00 00 19 00 00 00 09 00 00 00 80 3F DF EF 
08 14 12 07 05 84 40 DE 43 F7 83 82 19 01 00 80 38 47 4D 07 
00 CD E0 E8 5B BC 1C 8B D8 20 FD E0 E0 13 1C 1C 10 E7 00 DD 
E1 01 00 80 3A 07 EF 07 04 0E 0A F0 71 41 85 2D 07 FB 8D 60 
EF 5F 9C 1F EF F7 84 04 80 3F DF EF 08 13 C2 02 00 00 0D 00 
FE 00 04 00 01 00 00 00 00 00 00 00 00 01 03 00 01 00 00 00 
14 00 00 00 01 01 03 00 01 00 00 00 1A 00 00 00 02 01 03 00 
01 00 00 00 01 00 00 00 03 01 03 00 01 00 00 00 05 00 00 00 
06 01 03 00 01 00 00 00 01 00 00 00 11 01 04 00 04 00 00 00 
18 00 00 00 15 01 03 00 01 00 00 00 01 00 00 00 16 01 04 00 
01 00 00 00 08 00 00 00 17 01 04 00 04 00 00 00 28 00 00 00 
1A 01 05 00 01 00 00 00 08 00 00 00 1B 01 05 00 01 00 00 00 
10 00 00 00 28 01 03 00 01 00 00 00 02 00 00 00 00 00 00 00

But like I said, I don't know the format.

I'm now trying a method of taking the whole Byte value and ANDing it with a binary mask. So far, I've been unsuccessful though.

I'm seeing what looks like an LZW type compression. I'll show the compressed section in green. 0100 at the end of each section is a usual ending marker in LZ compression I'll show that in blue. There is also an interesting offset table that I'll show in red

Code:

49 49 2A 00 8A 00 00 00 58 02 00 00 01 00 00 00 58 02 00 00
01 00 00 00 38 00 00 00 4B 00 00 00 67 00 00 00 80 00 00 00 
13 00 00 00 1C 00 00 00 19 00 00 00 09 00 00 00 80 3F DF EF 
08 14 12 07 05 84 40 DE 43 F7 83 82 19 01 00 80 38 47 4D 07 
00 CD E0 E8 5B BC 1C 8B D8 20 FD E0 E0 13 1C 1C 10 E7 00 DD 
E1 01 00 80 3A 07 EF 07 04 0E 0A F0 71 41 85 2D 07 FB 8D 60 
EF 5F 9C 1F EF F7 84 04 80 3F DF EF 08 13 C2 02 00 00 0D 00 
FE 00 04 00 01 00 00 00 00 00 00 00 00 01 03 00 01 00 00 00 
14 00 00 00 01 01 03 00 01 00 00 00 1A 00 00 00 02 01 03 00 
01 00 00 00 01 00 00 00 03 01 03 00 01 00 00 00 05 00 00 00 
06 01 03 00 01 00 00 00 01 00 00 00 11 01 04 00 04 00 00 00 
18 00 00 00 15 01 03 00 01 00 00 00 01 00 00 00 16 01 04 00 
01 00 00 00 08 00 00 00 17 01 04 00 04 00 00 00 28 00 00 00 
1A 01 05 00 01 00 00 00 08 00 00 00 1B 01 05 00 01 00 00 00 
10 00 00 00 28 01 03 00 01 00 00 00 02 00 00 00 00 00 00 00

now the table of offsets seems to point to the start of each compressed section. look up LZW compression and I believe you'll have this figured out.

Hmm... then can anyone find a small, uncompressed, bitonal TIFF image I could try?

You're right. It is 20x26. My fault. I was looking under resolution, not size.