.TH "pngpack.c" 3 "Version 2.2.0" "NCEPLIBS-g2c" \" -*- nroff -*- .ad l .nh .SH NAME pngpack.c \- Pack data with PNG compression\&. .SH SYNOPSIS .br .PP \fC#include 'grib2_int\&.h'\fP .br \fC#include \fP .br \fC#include \fP .br .SS "Functions" .in +1c .ti -1c .RI "int \fBg2c_pngpackd\fP (double *fld, size_t width, size_t height, int *idrstmpl, unsigned char *cpack, int *lcpack)" .br .RI "This subroutine packs up a double data field into PNG image format\&. " .ti -1c .RI "int \fBg2c_pngpackf\fP (float *fld, size_t width, size_t height, int *idrstmpl, unsigned char *cpack, int *lcpack)" .br .RI "This subroutine packs up a float data field into PNG image format\&. " .ti -1c .RI "void \fBpngpack\fP (float *fld, \fBg2int\fP width, \fBg2int\fP height, \fBg2int\fP *idrstmpl, unsigned char *cpack, \fBg2int\fP *lcpack)" .br .RI "This subroutine packs up a float data field into PNG image format\&. " .ti -1c .RI "static int \fBpngpack_int\fP (void *fld, int fld_is_double, \fBg2int\fP width, \fBg2int\fP height, \fBg2int\fP *idrstmpl, unsigned char *cpack, \fBg2int\fP *lcpack, int verbose)" .br .RI "Packs float or double data into PNG image format\&. " .in -1c .SH "Detailed Description" .PP Pack data with PNG compression\&. .PP \fBAuthor\fP .RS 4 Stephen Gilbert .RE .PP \fBDate\fP .RS 4 2003-08-27 .RE .PP .PP Definition in file \fBpngpack\&.c\fP\&. .SH "Function Documentation" .PP .SS "int g2c_pngpackd (double * fld, size_t width, size_t height, int * idrstmpl, unsigned char * cpack, int * lcpack)" .PP This subroutine packs up a double data field into PNG image format\&. After the data field is scaled, and the reference value is subtracted out, it is treated as a grayscale image and passed to a PNG encoder\&. It also fills in GRIB2 Data Representation Template 5\&.41 or 5\&.40010 with the appropriate values\&. .PP \fBParameters\fP .RS 4 \fIfld\fP Pointer to array of double that contains the data values to pack\&. .br \fIwidth\fP Number of points in the x direction\&. .br \fIheight\fP Number of points in the y direction\&. .br \fIidrstmpl\fP Contains the array of values for Data Representation \fCTemplate 5\&.41\fP or 5\&.40010\&. .IP "\(bu" 2 0 Reference value - ignored on input, set by pngpack routine\&. .IP "\(bu" 2 1 Binary Scale Factor - used on input\&. .IP "\(bu" 2 2 Decimal Scale Factor - used on input\&. .IP "\(bu" 2 3 number of bits for each grayscale pixel value - ignored on input\&. .IP "\(bu" 2 4 Original field type - currently ignored on input, set = 0 on output\&. Data values assumed to be reals\&. .PP .br \fIcpack\fP The packed data field\&. .br \fIlcpack\fP length of packed field cpack\&. .RE .PP \fBReturns\fP .RS 4 .IP "\(bu" 2 \fBG2C_NOERROR\fP No error\&. .IP "\(bu" 2 \fBG2C_EPNG\fP Error encoding/decoding PNG data\&. .PP .RE .PP \fBAuthor\fP .RS 4 Ed Hartnett .RE .PP \fBDate\fP .RS 4 Aug 8, 2022 .RE .PP .PP Definition at line \fB348\fP of file \fBpngpack\&.c\fP\&. .PP References \fBG2C_PNG_DRS_TEMPLATE_LEN\fP, and \fBpngpack_int()\fP\&. .SS "int g2c_pngpackf (float * fld, size_t width, size_t height, int * idrstmpl, unsigned char * cpack, int * lcpack)" .PP This subroutine packs up a float data field into PNG image format\&. After the data field is scaled, and the reference value is subtracted out, it is treated as a grayscale image and passed to a PNG encoder\&. It also fills in GRIB2 Data Representation Template 5\&.41 or 5\&.40010 with the appropriate values\&. .PP \fBParameters\fP .RS 4 \fIfld\fP Pointer to array of float that contains the data values to pack\&. .br \fIwidth\fP Number of points in the x direction\&. .br \fIheight\fP Number of points in the y direction\&. .br \fIidrstmpl\fP Contains the array of values for Data Representation \fCTemplate 5\&.41\fP or 5\&.40010\&. .IP "\(bu" 2 0 Reference value - ignored on input, set by pngpack routine\&. .IP "\(bu" 2 1 Binary Scale Factor - used on input\&. .IP "\(bu" 2 2 Decimal Scale Factor - used on input\&. .IP "\(bu" 2 3 number of bits for each grayscale pixel value - ignored on input\&. .IP "\(bu" 2 4 Original field type - currently ignored on input, set = 0 on output\&. Data values assumed to be reals\&. .PP .br \fIcpack\fP The packed data field\&. .br \fIlcpack\fP length of packed field cpack\&. .RE .PP \fBReturns\fP .RS 4 .IP "\(bu" 2 \fBG2C_NOERROR\fP No error\&. .IP "\(bu" 2 \fBG2C_EPNG\fP Error encoding/decoding PNG data\&. .PP .RE .PP \fBAuthor\fP .RS 4 Ed Hartnett .RE .PP .PP Definition at line \fB294\fP of file \fBpngpack\&.c\fP\&. .PP References \fBG2C_PNG_DRS_TEMPLATE_LEN\fP, and \fBpngpack_int()\fP\&. .SS "void pngpack (float * fld, \fBg2int\fP width, \fBg2int\fP height, \fBg2int\fP * idrstmpl, unsigned char * cpack, \fBg2int\fP * lcpack)" .PP This subroutine packs up a float data field into PNG image format\&. After the data field is scaled, and the reference value is subtracted out, it is treated as a grayscale image and passed to a PNG encoder\&. It also fills in GRIB2 Data Representation Template 5\&.41 or 5\&.40010 with the appropriate values\&. .PP \fBParameters\fP .RS 4 \fIfld\fP Pointer to array of float that contains the data values to pack\&. .br \fIwidth\fP Number of points in the x direction\&. .br \fIheight\fP Number of points in the y direction\&. .br \fIidrstmpl\fP Contains the array of values for Data Representation \fCTemplate 5\&.41\fP or 5\&.40010\&. .IP "\(bu" 2 0 Reference value - ignored on input, set by pngpack routine\&. .IP "\(bu" 2 1 Binary Scale Factor - used on input\&. .IP "\(bu" 2 2 Decimal Scale Factor - used on input\&. .IP "\(bu" 2 3 number of bits for each grayscale pixel value - ignored on input\&. .IP "\(bu" 2 4 Original field type - currently ignored on input, set = 0 on output\&. Data values assumed to be reals\&. .PP .br \fIcpack\fP The packed data field\&. .br \fIlcpack\fP length of packed field cpack\&. .RE .PP \fBAuthor\fP .RS 4 Stephen Gilbert .RE .PP \fBDate\fP .RS 4 2003-08-27 .RE .PP \fBAuthor\fP .RS 4 Ed Hartnett .RE .PP .PP Definition at line \fB254\fP of file \fBpngpack\&.c\fP\&. .PP References \fBpngpack_int()\fP\&. .PP Referenced by \fBg2_addfield()\fP\&. .SS "static int pngpack_int (void * fld, int fld_is_double, \fBg2int\fP width, \fBg2int\fP height, \fBg2int\fP * idrstmpl, unsigned char * cpack, \fBg2int\fP * lcpack, int verbose)\fC [static]\fP" .PP Packs float or double data into PNG image format\&. This is called by \fBpngpack()\fP and pngpackd()\&. .PP After the data field is scaled, and the reference value is subtracted out, it is treated as a grayscale image and passed to a PNG encoder\&. It also fills in GRIB2 Data Representation Template 5\&.41 or 5\&.40010 with the appropriate values\&. .PP \fBParameters\fP .RS 4 \fIfld\fP Pointer to array of float or double that contains the data values to pack\&. .br \fIfld_is_double\fP If non-zero, then fld is double, otherwise float\&. .br \fIwidth\fP Number of points in the x direction\&. This is passed to the PNG layer as a uint32\&. .br \fIheight\fP Number of points in the y direction\&. This is passed to the PNG layer as a uint32\&. .br \fIidrstmpl\fP Contains the array of values for Data Representation \fCTemplate 5\&.41\fP or 5\&.40010\&. .IP "\(bu" 2 0 Reference value - ignored on input, set by pngpack routine\&. .IP "\(bu" 2 1 Binary Scale Factor - used on input\&. .IP "\(bu" 2 2 Decimal Scale Factor - used on input\&. .IP "\(bu" 2 3 number of bits for each grayscale pixel value - ignored on input\&. .IP "\(bu" 2 4 Original field type - currently ignored on input, set = 0 on output\&. Data values assumed to be reals\&. .PP .br \fIcpack\fP The packed data field\&. .br \fIlcpack\fP length of packed field cpack\&. .br \fIverbose\fP If non-zero, error messages will be printed in case of error\&. Otherwise, error codes will be return but no error messages printed\&. Calls to the original g2c API may cause error messages to be printed in case of error\&. For the new g2c_ API, no error messages will be printed - instead an error code will be returned\&. Call \fBg2c_strerror()\fP to get the error message for any error code\&. .RE .PP \fBReturns\fP .RS 4 .IP "\(bu" 2 \fBG2C_NOERROR\fP No error\&. .IP "\(bu" 2 \fBG2C_EPNG\fP Error encoding/decoding PNG data\&. .PP .RE .PP \fBAuthor\fP .RS 4 Ed Hartnett .RE .PP \fBDate\fP .RS 4 Aug 8, 2022 .RE .PP .PP Definition at line \fB53\fP of file \fBpngpack\&.c\fP\&. .PP References \fBALOG2\fP, \fBenc_png()\fP, \fBG2C_EPNG\fP, \fBG2C_NOERROR\fP, \fBint_power()\fP, \fBLOG\fP, \fBmkieee()\fP, and \fBsbits()\fP\&. .PP Referenced by \fBg2c_pngpackd()\fP, \fBg2c_pngpackf()\fP, and \fBpngpack()\fP\&. .SH "Author" .PP Generated automatically by Doxygen for NCEPLIBS-g2c from the source code\&.