Re: TIFF compression

From: vipin (vipin_at_nospam.com)
Date: 06/08/04 

Date: Tue, 8 Jun 2004 14:19:57 +0530

Hello,
         Whats the diference between "packbits" compression and "RLE"
compression for TIFF available in GDI+? Are they the same?

I vaguely read packbits uses RLE encoding, though I am not sure whether the
RLE scheme deployed in packbits is the same as the one used by the
RLEencoding scheme by the tiff encoder in GDI+. Can someone clarify?

thanks
vipin

"Aandi Inston" <quite@dial.pipex.con> wrote in message
news:40c4c1d5.362369199@reading.news.pipex.net...
> "vipin" <vipin@nospam.com> wrote:
>
> >Hi Aandi,
> >
> >You mean to say the ones supported by the GDI+ are the most recommended:-
> >none,rle,ccitt3,ccitt4,lzw are the most recommended ones.
>
> Definitely. I can think of no circumstances in which you should
> create any other compression - though it may be another story if you
> have to read arbitrary TIFF files.
> >
> >Do you have any idea of the libtiff library?
>
> It has a good reputation.
> >
> >I am checking it up for the first time, so got one doubt?
> >I saw a sample where for a Image of size (m *n).
> >
> >The memory allocated was (m * n * 3) bytes for a 24-bpp image. Doesn't
> >seem to be considering the
> >padding in DIB or DDB?
>
> Do TIFF files include such padding? From memory. they do not.
>
> Perhaps you are thinking too much of Windows formats. In my (limited)
> working with bitmap graphics, only BMP files use this strange
> convention. It's equally valid, of course, just out of line with
> everyone else.
> >
> >Do I need to strip the pad bytes for each scanline in the given .bmp
before
> >I can use it with libtiff?
>
> I would think so. Also, BMPs typically have the wrong pixel order.
> ----------------------------------------
> Aandi Inston quite@dial.pipex.com http://www.quite.com
> Please support usenet! Post replies and follow-ups, don't e-mail them.
>

Relevant Pages

  • Re: TIFF compression
    ... >I vaguely read packbits uses RLE encoding, though I am not sure whether the ... >RLEencoding scheme by the tiff encoder in GDI+. ... PackBits is an RLE compression method which works with any color ...
    (microsoft.public.win32.programmer.gdi)
  • Re: TIFF and JPEG
    ... I don't know about JPEG compression in TIFF standard. ... It looks like "your compressed TIFF" image is out of GDI+ ...
    (microsoft.public.dotnet.languages.csharp)
  • Re: OT: Early Fall
    ... Since you are not processing the jpg and then saving the file, the compression and decompression will not introduce noise into the photo. ... TIFF pictures store a single raster image at any color depth. ... Not all TIFF files are compatible with all programs that support the baseline TIFF standard. ... JPEG pictures store a single raster image in 24-bit color. ...
    (rec.boats)
  • Re: Nikon D40 or Canon XT or ?
    ... TIFF also offers lossy compression, ... BMP is one of the few image formats in use that ... And it's of course vastly smaller than BMP and does a very good ...
    (rec.photo.digital)
  • Re: Dissapearing Image
    ... This web site is a good source to understanding .tiff. ... Mary Sauer MSFT MVP ... the image color compression for images to lossless compression. ... and then click Microsoft Office Document Imaging. ...
    (microsoft.public.publisher)