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| author | giraffedata <giraffedata@9d0c8265-081b-0410-96cb-a4ca84ce46f8> | 2009-10-09 02:50:45 +0000 |
|---|---|---|
| committer | giraffedata <giraffedata@9d0c8265-081b-0410-96cb-a4ca84ce46f8> | 2009-10-09 02:50:45 +0000 |
| commit | 2032f45a59bda4a15d72b956f7eb9e7f4f4f4ea2 (patch) | |
| tree | 762d78b29871ce94a50291e6787a2b907ba0003b /jpeg2ktopam.html | |
| parent | baa73d1ea37c8aa6c59afa8aff7b8f63cac2b93b (diff) | |
| download | netpbm-mirror-2032f45a59bda4a15d72b956f7eb9e7f4f4f4ea2.tar.gz netpbm-mirror-2032f45a59bda4a15d72b956f7eb9e7f4f4f4ea2.tar.xz netpbm-mirror-2032f45a59bda4a15d72b956f7eb9e7f4f4f4ea2.zip | |
"miscellaneous update"
git-svn-id: http://svn.code.sf.net/p/netpbm/code/userguide@1003 9d0c8265-081b-0410-96cb-a4ca84ce46f8
Diffstat (limited to 'jpeg2ktopam.html')
| -rw-r--r-- | jpeg2ktopam.html | 61 |
1 files changed, 29 insertions, 32 deletions
diff --git a/jpeg2ktopam.html b/jpeg2ktopam.html index 1c3104da..daefeb41 100644 --- a/jpeg2ktopam.html +++ b/jpeg2ktopam.html @@ -2,15 +2,14 @@ <HTML><HEAD><TITLE>Jpeg2ktopam User Manual</TITLE></HEAD> <BODY> <H1>Jpeg2ktopam</H1> -Updated: 27 October 2002 +Updated: 08 October 2009 <BR> <A HREF="#index">Table Of Contents</A> <H2>NAME</H2> jpeg2ktopam - convert JPEG-2000 code stream to PAM/PNM -<A NAME="synopsis"> </A> -<H2>SYNOPSIS</H2> +<H2 id="synopsis">SYNOPSIS</H2> <B>jpeg2ktopam</B> [<B>-verbose</B>] @@ -23,26 +22,26 @@ jpeg2ktopam - convert JPEG-2000 code stream to PAM/PNM hyphens instead of single hyphen to denote options. You may use white space in place of the equals sign to separate an option name from its value. -<A NAME="description"> </A> -<H2>DESCRIPTION</H2> +<H2 id="description">DESCRIPTION</H2> <p>This program is part of <a href="index.html">Netpbm</a>. -<P><B>jpeg2ktopam</b> converts the named JPEG-2000 code stream file, +<P><B>jpeg2ktopam</b> converts the named JPEG-2000 file (JP2 or JPC), or Standard Input if no file is named, to a PBM, PGM, PPM, or PAM file on Standard Output. -<P>The JPEG-2000 specification specifies two different formats: JP2 -and JPEG-2000 code stream (JPC). JP2 represents a visual image quite -specifically, whereas JPC is a more or less arbitrary array of -codes. JP2 images are a subset of JPC images. <b>jpeg2ktopam</b> -converts any JPC image. If the color space identified in the image is -grayscale (JAS_IMAGE_CS_GRAY), <B>jpeg2ktopam</b> generates a PGM -image, unless the image contains only one bit per pixel, in which case -<b>jpeg2ktopam</b> generates PBM. If the color space is RGB -(JAS_IMAGE_CS_RGB), <b>jpeg2ktopam</b> generates a PPM image. If the -input image is anything else, <b>jpeg2ktopam</b> generates a PAM image -with no tuple type identified. +<P>The JPEG-2000 specification specifies two different formats: JP2 and +JPEG-2000 code stream (JPC). JP2 represents a visual image quite +specifically, whereas JPC is a more or less arbitrary array of codes. A JP2 +image contains a JPC stream and metadata describing how that stream represents +a visual image. <b>jpeg2ktopam</b> converts both. + +<p>If the color space identified in the image is grayscale +(JAS_IMAGE_CS_GRAY), <B>jpeg2ktopam</b> generates a PGM image, unless the +image contains only one bit per pixel, in which case <b>jpeg2ktopam</b> +generates PBM. If the color space is RGB (JAS_IMAGE_CS_RGB), +<b>jpeg2ktopam</b> generates a PPM image. If the input image is anything +else, <b>jpeg2ktopam</b> generates a PAM image with no tuple type identified. <P>In the PGM and PPM cases, <b>jpeg2ktopam</b> assumes the intensity values in the input image have the same meaning as for PGM and PPM. @@ -58,17 +57,17 @@ represented in two's complement form in the output (because PAM samples are always unsigned). The PAM plane numbers are identical to the JPC component numbers. -<p>A JPC image has a "precision," which is the number of bits used for +<p>A JPEG-2000 image has a "precision," which is the number of bits used for each code (in Netpbm lingo, "sample"). Actually, each component has a separate precision. The maxval of a PGM, PPM, or PAM output is the -largest number you can represent in the JPC precision of the JPC +largest number you can represent in the JPEG-2000 precision of the JPEG-2000 component with the greatest precision. The samples in all components are scaled to that maxval. So if the red component has a precision of 4 bits and the green component has a precision of 6 bits, the maxval is 63 and -the red component codes from the JPC image are multiplied by 63/15 to +the red component codes from the JPEG-2000 image are multiplied by 63/15 to generate the output samples. -<P><b>jpeg2ktopam</b> interprets the JPC input with the <a +<P><b>jpeg2ktopam</b> interprets the JPEG-2000 input with the <a href="http://www.ece.uvic.ca/~mdadams/jasper/">Jasper JPEG-2000 library</a>. See documentation of the library for details on what <b>jpeg2ktopam</b> handles. Note that the Jasper library contains @@ -87,8 +86,7 @@ especially recently added features. However, since it does not use the Netpbm library to read and write the Netpbm formats, it doesn't do as good a job on that side. -<A NAME="options"> </A> -<H2>OPTIONS</H2> +<H2 id="options">OPTIONS</H2> <DL COMPACT> @@ -101,29 +99,25 @@ messages about the conversion process. <DD>This option controls debug messages from the Jasper library. <b>jpeg2ktopam</b> passes <i>number</i> as the debug level to the Jasper -JPC decoder. +JPEG-2000 decoder. </DL> -<A NAME="examples"> </A> -<H2>EXAMPLES</H2> +<H2 id="examples">EXAMPLES</H2> <pre> jpeg2ktopam myimg.jpc >myimg.ppm </pre> -<A NAME="jpeg2000"> </A> -<H2>ABOUT JPEG-2000</H2> +<H2 id="jpeg2000">ABOUT JPEG-2000</H2> <p>See <a href="pamtojpeg2k.html">the <b>pamtojpeg2k</b> manual</a> for general information on JPEG-2000 compression and the JPEG-2000 formats. - -<A NAME="seealso"> </A> -<H2>SEE ALSO</H2> +<H2 kd="seealso">SEE ALSO</H2> <B><A HREF="pamtojpeg2k.html">jpctopam</A></B>, <B><A HREF="jpegtopnm.html">pnmtopeg</A></B>, @@ -136,8 +130,11 @@ JPEG-2000 formats. <p><b>jpeg2ktopam</b> was added to Netpbm in Release 10.12 (November 2002). +<p>Before Netpbm 10.49 (December 2009), <b>jpeg2ktopam</b> could not convert +a JP2 file -- only JPC. + <HR> -<A NAME="index"> </A><H2>Table Of Contents</H2> +<H2 id="index">Table Of Contents</H2> <UL> <LI><A HREF="#synopsis">SYNOPSIS</A> <LI><A HREF="#description">DESCRIPTION</A> |