.TH "jpcpack.c" 3 "Fri Jun 3 2022" "Version 1.6.4" "NCEPLIBS-g2c" \" -*- nroff -*-
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.SH NAME
jpcpack.c \- Pack up a data field into a JPEG2000 code stream\&.  

.SH SYNOPSIS
.br
.PP
\fC#include <stdlib\&.h>\fP
.br
\fC#include <math\&.h>\fP
.br
\fC#include 'grib2\&.h'\fP
.br

.SS "Functions"

.in +1c
.ti -1c
.RI "int \fBenc_jpeg2000\fP (unsigned char *, \fBg2int\fP, \fBg2int\fP, \fBg2int\fP, \fBg2int\fP, \fBg2int\fP, \fBg2int\fP, char *, \fBg2int\fP)"
.br
.RI "This Function encodes a grayscale image into a JPEG2000 code stream specified in the JPEG2000 Part-1 standard (i\&.e\&., ISO/IEC 15444-1) using JasPer Software version 1\&.500\&.4 (or 1\&.700\&.2) written by the University of British Columbia, Image Power Inc, and others\&. "
.ti -1c
.RI "void \fBjpcpack\fP (\fBg2float\fP *fld, \fBg2int\fP width, \fBg2int\fP height, \fBg2int\fP *idrstmpl, unsigned char *cpack, \fBg2int\fP *lcpack)"
.br
.RI "This subroutine packs up a data field into a JPEG2000 code stream\&. "
.in -1c
.SH "Detailed Description"
.PP 
Pack up a data field into a JPEG2000 code stream\&. 


.PP
\fBAuthor\fP
.RS 4
Stephen Gilbert 
.RE
.PP
\fBDate\fP
.RS 4
2003-08-17 
.RE
.PP

.PP
Definition in file \fBjpcpack\&.c\fP\&.
.SH "Function Documentation"
.PP 
.SS "int enc_jpeg2000 (unsigned char * cin, \fBg2int\fP width, \fBg2int\fP height, \fBg2int\fP nbits, \fBg2int\fP ltype, \fBg2int\fP ratio, \fBg2int\fP retry, char * outjpc, \fBg2int\fP jpclen)"

.PP
This Function encodes a grayscale image into a JPEG2000 code stream specified in the JPEG2000 Part-1 standard (i\&.e\&., ISO/IEC 15444-1) using JasPer Software version 1\&.500\&.4 (or 1\&.700\&.2) written by the University of British Columbia, Image Power Inc, and others\&. JasPer is available at http://www.ece.uvic.ca/~mdadams/jasper/\&.
.PP
PROGRAM HISTORY LOG:
.IP "\(bu" 2
2002-12-02 Gilbert
.IP "\(bu" 2
2004-12-16 Gilbert - Added retry argument/option to allow option of increasing the maximum number of guard bits to the JPEG2000 algorithm\&.
.PP
.PP
\fBParameters\fP
.RS 4
\fIcin\fP Packed matrix of Grayscale image values to encode\&. 
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\fIwidth\fP width of image\&. 
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\fIheight\fP height of image\&. 
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\fInbits\fP depth (in bits) of image\&. i\&.e number of bits used to hold each data value\&. 
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\fIltype\fP indicator of lossless or lossy compression\&.
.IP "\(bu" 2
1, for lossy compression
.IP "\(bu" 2
!= 1, for lossless compression 
.PP
.br
\fIratio\fP target compression ratio\&. (ratio:1) Used only when ltype == 1\&. 
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\fIretry\fP Pointer to option type\&. If 1 try increasing number of guard bits otherwise, no additional options\&. 
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\fIoutjpc\fP Output encoded JPEG2000 code stream\&. 
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\fIjpclen\fP Number of bytes allocated for new JPEG2000 code stream in outjpc\&.
.RE
.PP
\fBReturns\fP
.RS 4
.IP "\(bu" 2
> 0 = Length in bytes of encoded JPEG2000 code stream
.IP "\(bu" 2
-3 = Error decode jpeg2000 code stream\&.
.IP "\(bu" 2
-5 = decoded image had multiple color components\&. Only grayscale is expected\&.
.PP
.RE
.PP
\fBNote\fP
.RS 4
Requires JasPer Software version 1\&.500\&.4 or 1\&.700\&.2\&.
.RE
.PP
\fBAuthor\fP
.RS 4
Stephen Gilbert 
.RE
.PP
\fBDate\fP
.RS 4
2002-12-02 
.RE
.PP

.PP
Definition at line 56 of file enc_jpeg2000\&.c\&.
.PP
References MAXOPTSSIZE\&.
.PP
Referenced by jpcpack()\&.
.SS "void jpcpack (\fBg2float\fP * fld, \fBg2int\fP width, \fBg2int\fP height, \fBg2int\fP * idrstmpl, unsigned char * cpack, \fBg2int\fP * lcpack)"

.PP
This subroutine packs up a data field into a JPEG2000 code stream\&. After the data field is scaled, and the reference value is subtracted out, it is treated as a grayscale image and passed to a JPEG2000 encoder\&. It also fills in GRIB2 Data Representation Template 5\&.40 or 5\&.40000 with the appropriate values\&.
.PP
PROGRAM HISTORY LOG:
.IP "\(bu" 2
2003-08-17 Gilbert
.IP "\(bu" 2
2004-11-92 Gilbert - Fixed bug encountered when packing a near constant field\&.
.IP "\(bu" 2
2004-07-19 Gilbert - Added check on whether the jpeg2000 encoding was successful\&. If not, try again with different encoder options\&.
.IP "\(bu" 2
2005-05-10 Gilbert - Imposed minimum size on cpack, used to hold encoded bit string\&.
.PP
.PP
\fBParameters\fP
.RS 4
\fIfld\fP Contains the data values to pack\&. 
.br
\fIwidth\fP number of points in the x direction\&. 
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\fIheight\fP number of points in the y direction\&. 
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\fIidrstmpl\fP Contains the array of values for Data Representation Template 5\&.40 or 5\&.40000\&.
.IP "\(bu" 2
0 Reference value - ignored on input, set by jpcpack routine\&.
.IP "\(bu" 2
1 Binary Scale Factor - used on input, unchanged by jpcpack routine\&.
.IP "\(bu" 2
2 Decimal Scale Factor - used on input, unchanged by jpcpack routine\&.
.IP "\(bu" 2
3 number of bits for each data value - ignored on input
.IP "\(bu" 2
4 Original field type - currently ignored on input Data values assumed to be reals\&. Set to 0 on output\&.
.IP "\(bu" 2
5 if 0 use lossless compression, if 1 use lossy compression\&.
.IP "\(bu" 2
6 Desired compression ratio, if idrstmpl[5]=1\&. Set to 255, if idrstmpl[5]=0\&. 
.PP
.br
\fIcpack\fP The packed data field\&. 
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\fIlcpack\fP length of packed field in cpack\&.
.RE
.PP
\fBAuthor\fP
.RS 4
Stephen Gilbert 
.RE
.PP
\fBDate\fP
.RS 4
2003-08-17 
.RE
.PP

.PP
Definition at line 49 of file jpcpack\&.c\&.
.PP
References enc_jpeg2000(), int_power(), mkieee(), and sbits()\&.
.PP
Referenced by g2_addfield()\&.
.SH "Author"
.PP 
Generated automatically by Doxygen for NCEPLIBS-g2c from the source code\&.