.\" t
.\" @(#)export.3		01/24/2017
.TH export 3x "AfterStep v.2.2.12" "Jan 24 2017" "AfterStep X11 window manager"
.UC
.SH NAME
\fBexport\fP\ \- functionality for writing images into files
libAfterImage/export\&.h
.SH NAMEexport
\- Image output into different file formats\&.

.SH SEE ALSO
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Structures :
         ASXpmExportParams
         ASPngExportParams
         ASJpegExportParams
         ASGifExportParams
         ASImageExportParams

Functions :
        ASImage2file()

Other libAfterImage modules :
         ascmap\&.h asfont\&.h asimage\&.h asvisual\&.h blender\&.h export\&.h
         import\&.h transform\&.h ximage\&.h
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.SH AUTHOR
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Sasha Vasko <sasha at aftercode dot net>
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libAfterImage/ExportFlags
.SH NAMEEXPORT_GRAYSCALE
\- save image as grayscale\&.
EXPORT_ALPHA
\- save alpha channel if format permits
EXPORT_APPEND
\- if format allows multiple images \- image will be appended

.SH FUNCTION
.fi
Some common flags that could be used while writing images into
different file formats\&.
.fi

.SH SOURCE
.in +4n

.fi
#define EXPORT_GRAYSCALE            (0x01<<0)
#define EXPORT_ALPHA                (0x01<<1)
#define EXPORT_APPEND               (0x01<<3)  /* adds subimage  */
#define EXPORT_ANIMATION_REPEATS    (0x01<<4)  /* number of loops to repeat GIF animation */
/*****/
.fi

.in
libAfterImage/ASPngExportParams
.SH NAMEASPngExportParams
\- parameters for export into PNG file\&.

.SH SOURCE
.in +4n

.fi
typedef struct
{
    ASImageFileTypes type;
    ASFlagType flags ;
    int compression ;
}ASPngExportParams ;
.fi

.in
libAfterImage/ASJpegExportParams
.SH NAMEASJpegExportParams
\- parameters for export into JPEG file\&.

.SH SOURCE
.in +4n

.fi
typedef struct
{
    ASImageFileTypes type;
    ASFlagType flags ;
    int quality ;
}ASJpegExportParams ;
.fi

.in
libAfterImage/ASGifExportParams
.SH NAMEASGifExportParams
\- parameters for export into GIF file\&.

.SH SOURCE
.in +4n

.fi
typedef struct
{
    ASImageFileTypes type;
    ASFlagType flags ;
    int dither ;
    int opaque_threshold ;
    unsigned short animate_delay ;
    unsigned short animate_repeats ;
}ASGifExportParams ;
.fi

.in
libAfterImage/ASTiffExportParams
.SH NAMEASTiffExportParams
\- parameters for export into TIFF file\&.

.SH SOURCE
.in +4n

.fi
typedef struct
{
    ASImageFileTypes type;
    ASFlagType flags ;
    CARD32 rows_per_strip ;

/* these are suitable compressions : */
#define TIFF_COMPRESSION_NONE       1
#define TIFF_COMPRESSION_OJPEG      6   /* !6\&.0 JPEG */
#define TIFF_COMPRESSION_JPEG       7
#define TIFF_COMPRESSION_PACKBITS   32773   /* Macintosh RLE */
#define TIFF_COMPRESSION_DEFLATE    32946   /* Deflate compression */
    /* you should be able to use other values from tiff\&.h as well */
    CARD32 compression_type ;
    int jpeg_quality ;

    int opaque_threshold ;
}ASTiffExportParams ;
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.in
libAfterImage/ASImageExportParams
.SH NAMEASImageExportParams
\- union of structures holding parameters for export into different file formats\&.

.SH DESCRIPTION
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Treatment of this union depends on what type of export was requested\&.
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.SH SEE ALSO
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ASImageFileTypes
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.SH SOURCE
.in +4n

.fi
typedef union ASImageExportParams
{
    ASImageFileTypes   type;
    ASXpmExportParams  xpm;
    ASPngExportParams  png;
    ASJpegExportParams jpeg;
    ASGifExportParams  gif;
    ASTiffExportParams tiff;
}ASImageExportParams;
.fi

.in
libAfterImage/export/ASImage2file()
.SH NAMEASImage2file()


.SH SYNOPSIS
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Bool ASImage2file( ASImage *im, const char *dir, const char *file,
              ASImageFileTypes type, ASImageExportParams *params );
.fi

.SH INPUTS
.IP "im"
\- Image to write out\&.
.IP "dir"
\- directory name to write file into (optional, could be NULL)
.IP "file"
\- file name with or without directory name\&.
.IP "type"
\- output file format\&. ( see ASImageFileTypes )
.IP "params"
\- pointer to ASImageExportParams union's member for the above type, with additional export parameters, such as quality, compression, etc\&. If NULL then all defaults will be used\&.

.SH RETURN VALUE
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True on success\&. False \- failure\&.
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.SH DESCRIPTION
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ASImage2file will construct filename out of dir and file components
and then will call specific filter to write out file in requested
format\&.
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.SH NOTES
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Some formats support compression, others support lossy compression,
yet others allows you to limit number of colors and colordepth\&.
Each specific filter will try to interpret those parameters in its
own way\&.
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.SH EXAMPLE
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asmerge\&.c: ASMerge\&.3
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