VipsForeign

typedef struct _VipsForeign VipsForeign;

VipsForeignClass

typedef struct {
	VipsOperationClass parent_class;


	/* Loop over formats in this order, default 0. We need this because
	 * some formats can be read by several loaders (eg. tiff can be read
	 * by the libMagick loader as well as by the tiff loader), and we want
	 * to make sure the better loader comes first.
	 */
	int priority;

	/* Null-terminated list of recommended suffixes, eg. ".tif", ".tiff".
	 * This can be used by both load and save, so it's in the base class.
	 */
	const char **suffs;
} VipsForeignClass;

The suffix list is used to select a format to save a file in, and to pick a loader if you don't define is_a().

You should also define nickname and description in VipsObject.

enum VipsForeignFlags

typedef enum {
	VIPS_FOREIGN_NONE = 0,		/* No flags set */
	VIPS_FOREIGN_PARTIAL = 1, /* Lazy read OK (eg. tiled tiff) */
	VIPS_FOREIGN_SEQUENTIAL = 2, /* Top-to-bottom lazy read OK */
	VIPS_FOREIGN_BIGENDIAN = 4, /* Most-significant byte first */
	VIPS_FOREIGN_ALL = 7		/* All flags set */
} VipsForeignFlags;

Some hints about the image loader.

VIPS_FOREIGN_PARTIAL means that the image can be read directly from the file without needing to be unpacked to a temporary image first.

VIPS_FOREIGN_SEQUENTIAL means that the loader supports lazy reading, but only top-to-bottom (sequential) access. Formats like PNG can read sets of scanlines, for example, but only in order.

If neither PARTIAL or SEQUENTIAL is set, the loader only supports whole image read. Setting both PARTIAL and SEQUENTIAL is an error.

VIPS_FOREIGN_BIGENDIAN means that image pixels are most-significant byte first. Depending on the native byte order of the host machine, you may need to swap bytes. See copy_swap().

VipsForeignLoad

typedef struct {
	/* The image we generate. This must be set by ->header().
	 */
	VipsImage *out;

	/* The behind-the-scenes real image we decompress to. This can be a
	 * disc foreign or a memory buffer. This must be set by ->load().
	 */
	VipsImage *real;
} VipsForeignLoad;

header() must set at least the header fields of out. laod(), if defined, must load the pixels to real.

VipsForeignLoadClass

typedef struct {
	VipsForeignClass parent_class;

	/* Is a file in this format. 
	 *
	 * This function should return %TRUE if the file contains an image of 
	 * this type. If you don't define this function, #VipsForeignLoad
	 * will use @suffs instead.
	 */
	gboolean (*is_a)( const char * );

	/* Get the flags from a filename. 
	 *
	 * This function should examine the file and return a set
	 * of flags. If you don't define it, vips will default to 0 (no flags 
	 * set).  
	 *
	 * This operation is necessary for vips7 compatibility. 
	 */
	VipsForeignFlags (*get_flags_filename)( const char * );

	/* Get the flags for this load operation. Images can be loaded from 
	 * (for example) memory areas rather than files, so you can't just use
	 * @get_flags_filename().
	 */
	VipsForeignFlags (*get_flags)( VipsForeignLoad * );

	/* Do the minimum read we can. 
	 *
	 * Set the header fields in @out from @filename. If you can read the 
	 * whole image as well with no performance cost (as with vipsload),
	 * or if your loader does not support reading only the header, read
	 * the entire image in this method and leave @load() NULL.
	 *
	 * @header() needs to set the dhint on the image .. otherwise you get 
	 * the default SMALLTILE.
	 *
	 * Return 0 for success, -1 for error, setting
	 * vips_error().
	 */
	int (*header)( VipsForeignLoad * );

	/* Read the whole image into @real. The pixels will get copied to @out 
	 * later.
	 *
	 * You can omit this method if you define a @header() method which 
	 * loads the whole file. 
	 *
	 * Return 0 for success, -1 for error, setting
	 * vips_error().
	 */
	int (*load)( VipsForeignLoad * );
} VipsForeignLoadClass;

Add a new loader to VIPS by subclassing VipsForeignLoad. Subclasses need to implement at least header().

As a complete example, here's the code for the PNG loader, minus the actual calls to libpng.

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typedef struct _VipsForeignLoadPng {
    VipsForeignLoad parent_object;

    char *filename; 
} VipsForeignLoadPng;

typedef VipsForeignLoadClass VipsForeignLoadPngClass;

G_DEFINE_TYPE( VipsForeignLoadPng, vips_foreign_load_png, 
    VIPS_TYPE_FOREIGN_LOAD );

static VipsForeignFlags
vips_foreign_load_png_get_flags_filename( const char *filename )
{
    VipsForeignFlags flags;

    flags = 0;
    if( vips__png_isinterlaced( filename ) )
        flags = VIPS_FOREIGN_PARTIAL;
    else
        flags = VIPS_FOREIGN_SEQUENTIAL;

    return( flags );
}

static VipsForeignFlags
vips_foreign_load_png_get_flags( VipsForeignLoad *load )
{
    VipsForeignLoadPng *png = (VipsForeignLoadPng *) load;

    return( vips_foreign_load_png_get_flags_filename( png->filename ) );
}

static int
vips_foreign_load_png_header( VipsForeignLoad *load )
{
    VipsForeignLoadPng *png = (VipsForeignLoadPng *) load;

    if( vips__png_header( png->filename, load->out ) )
        return( -1 );

    return( 0 );
}

static int
vips_foreign_load_png_load( VipsForeignLoad *load )
{
    VipsForeignLoadPng *png = (VipsForeignLoadPng *) load;

    if( vips__png_read( png->filename, load->real ) )
        return( -1 );

    return( 0 );
}

static void
vips_foreign_load_png_class_init( VipsForeignLoadPngClass *class )
{
    GObjectClass *gobject_class = G_OBJECT_CLASS( class );
    VipsObjectClass *object_class = (VipsObjectClass *) class;
    VipsForeignClass *foreign_class = (VipsForeignClass *) class;
    VipsForeignLoadClass *load_class = (VipsForeignLoadClass *) class;

    gobject_class->set_property = vips_object_set_property;
    gobject_class->get_property = vips_object_get_property;

    object_class->nickname = "pngload";
    object_class->description = _( "load png from file" );

    foreign_class->suffs = vips__png_suffs;

    load_class->is_a = vips__png_ispng;
    load_class->get_flags_filename = 
        vips_foreign_load_png_get_flags_filename;
    load_class->get_flags = vips_foreign_load_png_get_flags;
    load_class->header = vips_foreign_load_png_header;
    load_class->load = vips_foreign_load_png_load;

    VIPS_ARG_STRING( class, "filename", 1, 
        _( "Filename" ),
        _( "Filename to load from" ),
        VIPS_ARGUMENT_REQUIRED_INPUT, 
        G_STRUCT_OFFSET( VipsForeignLoadPng, filename ),
        NULL );
}

static void
vips_foreign_load_png_init( VipsForeignLoadPng *png )
{
}

VipsForeignSave

typedef struct {
	/* The image we are to save, as supplied by our caller. 
	 */
	VipsImage *in;

	/* @in converted to a saveable format (eg. 8-bit RGB) according to the
	 * instructions you give in the class fields below.
	 *
	 * This is the image you should actually write to the output.
	 */
	VipsImage *ready;
} VipsForeignSave;

VipsForeignSaveClass

typedef struct {
	VipsForeignClass parent_class;


	/* How this format treats bands.
	 *
	 * @saveable describes the bands that your saver can handle. For 
	 * example, PPM images can have 1 or 3 bands (mono or RGB), so it 
	 * uses #VIPS_SAVEABLE_RGB.
	 */
	VipsSaveable saveable;

	/* How this format treats band formats.
	 *
	 * @format_table describes the band formats that your saver can 
	 * handle. For each of the 10 #VipsBandFormat values, the array 
	 * should give the format your saver will accept. 
	 */
	VipsBandFormat *format_table;

	/* The set of coding types this format can save. For example, jpeg can
	 * only save NONE, so has NONE TRUE and RAD and LABQ FALSE.
	 *
	 * Default NONE TRUE, RAD and LABQ FALSE.
	 */
	gboolean coding[VIPS_CODING_LAST];
} VipsForeignSaveClass;

Call your saver in the class' build() method after chaining up. The prepared image should be ready for you to save in ready.

As a complete example, here's the code for the CSV saver, minus the calls to the actual save routines.

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typedef struct _VipsForeignSaveCsv {
    VipsForeignSave parent_object;

    char *filename; 
    const char *separator;
} VipsForeignSaveCsv;

typedef VipsForeignSaveClass VipsForeignSaveCsvClass;

G_DEFINE_TYPE( VipsForeignSaveCsv, vips_foreign_save_csv, 
    VIPS_TYPE_FOREIGN_SAVE );

static int
vips_foreign_save_csv_build( VipsObject *object )
{
    VipsForeignSave *save = (VipsForeignSave *) object;
    VipsForeignSaveCsv *csv = (VipsForeignSaveCsv *) object;

    if( VIPS_OBJECT_CLASS( vips_foreign_save_csv_parent_class )->
        build( object ) )
        return( -1 );

    if( vips__csv_write( save->ready, csv->filename, csv->separator ) )
        return( -1 );

    return( 0 );
}

#define UC VIPS_FORMAT_UCHAR
#define C VIPS_FORMAT_CHAR
#define US VIPS_FORMAT_USHORT
#define S VIPS_FORMAT_SHORT
#define UI VIPS_FORMAT_UINT
#define I VIPS_FORMAT_INT
#define F VIPS_FORMAT_FLOAT
#define X VIPS_FORMAT_COMPLEX
#define D VIPS_FORMAT_DOUBLE
#define DX VIPS_FORMAT_DPCOMPLEX

static int bandfmt_csv[10] = {
// UC  C   US  S   UI  I  F  X  D  DX 
   UC, C,  US, S,  UI, I, F, X, D, DX
};

static void
vips_foreign_save_csv_class_init( VipsForeignSaveCsvClass *class )
{
    GObjectClass *gobject_class = G_OBJECT_CLASS( class );
    VipsObjectClass *object_class = (VipsObjectClass *) class;
    VipsForeignClass *foreign_class = (VipsForeignClass *) class;
    VipsForeignSaveClass *save_class = (VipsForeignSaveClass *) class;

    gobject_class->set_property = vips_object_set_property;
    gobject_class->get_property = vips_object_get_property;

    object_class->nickname = "csvsave";
    object_class->description = _( "save image to csv file" );
    object_class->build = vips_foreign_save_csv_build;

    foreign_class->suffs = vips__foreign_csv_suffs;

    save_class->saveable = VIPS_SAVEABLE_MONO;
    save_class->format_table = bandfmt_csv;

    VIPS_ARG_STRING( class, "filename", 1, 
        _( "Filename" ),
        _( "Filename to save to" ),
        VIPS_ARGUMENT_REQUIRED_INPUT, 
        G_STRUCT_OFFSET( VipsForeignSaveCsv, filename ),
        NULL );

    VIPS_ARG_STRING( class, "separator", 13, 
        _( "Separator" ), 
        _( "Separator characters" ),
        VIPS_ARGUMENT_OPTIONAL_INPUT,
        G_STRUCT_OFFSET( VipsForeignSaveCsv, separator ),
        "\t" ); 
}

static void
vips_foreign_save_csv_init( VipsForeignSaveCsv *csv )
{
    csv->separator = g_strdup( "\t" );
}

enum VipsForeignTiffCompression

typedef enum {
	VIPS_FOREIGN_TIFF_COMPRESSION_NONE,
	VIPS_FOREIGN_TIFF_COMPRESSION_JPEG,
	VIPS_FOREIGN_TIFF_COMPRESSION_DEFLATE,
	VIPS_FOREIGN_TIFF_COMPRESSION_PACKBITS,
	VIPS_FOREIGN_TIFF_COMPRESSION_CCITTFAX4,
	VIPS_FOREIGN_TIFF_COMPRESSION_LZW,
	VIPS_FOREIGN_TIFF_COMPRESSION_LAST
} VipsForeignTiffCompression;

The compression types supported by the tiff writer.

Use Q to set the jpeg compression level, default 75.

Use prediction to set the lzw or deflate prediction, default none.

enum VipsForeignTiffPredictor

typedef enum {
	VIPS_FOREIGN_TIFF_PREDICTOR_NONE = 1,
	VIPS_FOREIGN_TIFF_PREDICTOR_HORIZONTAL = 2,
	VIPS_FOREIGN_TIFF_PREDICTOR_FLOAT = 3,
	VIPS_FOREIGN_TIFF_PREDICTOR_LAST
} VipsForeignTiffPredictor;

The predictor can help deflate and lzw compression. The values are fixed by the tiff library.

enum VipsForeignTiffResunit

typedef enum {
	VIPS_FOREIGN_TIFF_RESUNIT_CM,
	VIPS_FOREIGN_TIFF_RESUNIT_INCH,
	VIPS_FOREIGN_TIFF_RESUNIT_LAST
} VipsForeignTiffResunit;

Use inches or centimeters as the resolution unit for a tiff file.

enum VipsSaveable

typedef enum {
	VIPS_SAVEABLE_MONO,
	VIPS_SAVEABLE_RGB,
	VIPS_SAVEABLE_RGBA,
	VIPS_SAVEABLE_RGB_CMYK,
	VIPS_SAVEABLE_ANY,
	VIPS_SAVEABLE_LAST
} VipsSaveable;

See also: VipsForeignSave.

vips_analyzeload ()

int                 vips_analyzeload                    (const char *filename,
                                                         VipsImage **out,
                                                         ...);

Load an Analyze 6.0 file. If filename is "fred.img", this will look for an image header called "fred.hdr" and pixel data in "fred.img". You can also load "fred" or "fred.hdr".

Images are loaded lazilly and byte-swapped, if necessary. The Analyze metadata is read and attached.

See also: vips_image_new_from_file().

vips_csvload ()

int                 vips_csvload                        (const char *filename,
                                                         VipsImage **out,
                                                         ...);

Optional arguments:

skip: skip this many lines at start of file lines: read this many lines from file whitespace: set of whitespace characters separator: set of separator characters

Load a CSV (comma-separated values) file. The output image is always 1 band (monochrome), VIPS_FORMAT_DOUBLE.

Items in lines can be either floating point numbers in the C locale, or strings enclosed in double-quotes ("), or empty. You can use a backslash (\) within the quotes to escape special characters, such as quote marks.

The reader is deliberately rather fussy: it will fail if there are any short lines, or if the file is too short. It will ignore lines that are too long.

skip sets the number of lines to skip at the start of the file. Default zero.

lines sets the number of lines to read from the file. Default -1, meaning read all lines to end of file.

whitespace sets the skippable whitespace characters. Default space. Whitespace characters are always run together.

separator sets the characters that separate fields. Default ;,tab. Separators are never run together.

See also: vips_image_new_from_file().

vips_csvsave ()

int                 vips_csvsave                        (VipsImage *in,
                                                         const char *filename,
                                                         ...);

Optional arguments:

separator: separator string

Writes the pixels in in to the filename as CSV (comma-separated values). The image is written one line of text per scanline. Complex numbers are written as "(real,imaginary)" and will need extra parsing I guess. Only the first band is written.

separator gives the string to use to separate numbers in the output. The default is "\\t" (tab).

See also: vips_image_write_file().

vips_fitsload ()

int                 vips_fitsload                       (const char *filename,
                                                         VipsImage **out,
                                                         ...);

Read a FITS image file into a VIPS image.

See also: vips_image_new_from_file().

vips_fitssave ()

int                 vips_fitssave                       (VipsImage *in,
                                                         const char *filename,
                                                         ...);

Write a VIPS image to a file as FITS.

See also: vips_image_write_file().

vips_foreign_find_load ()

const char *        vips_foreign_find_load              (const char *filename);

Searches for an operation you could use to load filename.

See also: vips_foreign_read().

vips_foreign_find_load_options ()

const char *        vips_foreign_find_load_options      (const char *filename);

Searches for an operation you could use to load filename.

Arguments to the loader may be embedded in the filename using the usual syntax.

See also: vips_foreign_load().

vips_foreign_find_save ()

const char *        vips_foreign_find_save              (const char *filename);

Searches for an operation you could use to write to filename.

filename may not contain embedded options. See vips_foreign_find_save_options() if your filename may have options in.

See also: vips_foreign_write().

vips_foreign_find_save_options ()

const char *        vips_foreign_find_save_options      (const char *filename);

Searches for an operation you could use to write to filename.

filename may contain embedded options. See vips_foreign_find_save() if your filename does not options in.

See also: vips_foreign_write().

vips_foreign_flags ()

VipsForeignFlags    vips_foreign_flags                  (const char *loader,
                                                         const char *filename);

Return the flags for filename using loader. loader is something like "tiffload" or "VipsForeignLoadTiff".

vips_foreign_is_a ()

gboolean            vips_foreign_is_a                   (const char *loader,
                                                         const char *filename);

Return TRUE if filename can be loaded by loader. loader is something like "tiffload" or "VipsForeignLoadTiff".

vips_foreign_load ()

int                 vips_foreign_load                   (const char *filename,
                                                         VipsImage **out,
                                                         ...);

Loads filename into out using the loader recommended by vips_foreign_find_load().

See also: vips_foreign_save(), vips_foreign_load_options().

vips_foreign_load_options ()

int                 vips_foreign_load_options           (const char *filename,
                                                         VipsImage **out);

Loads filename into out using the loader recommended by vips_foreign_find_load().

Arguments to the loader may be embedded in the filename using the usual syntax.

See also: vips_foreign_load().

vips_foreign_map ()

void *              vips_foreign_map                    (const char *base,
                                                         VipsSListMap2Fn fn,
                                                         void *a,
                                                         void *b);

Apply a function to every VipsForeignClass that VIPS knows about. Foreigns are presented to the function in priority order.

Like all VIPS map functions, if fn returns NULL, iteration continues. If it returns non-NULL, iteration terminates and that value is returned. The map function returns NULL if all calls return NULL.

See also: vips_slist_map().

vips_foreign_operation_init ()

void                vips_foreign_operation_init         (void);

vips_foreign_save ()

int                 vips_foreign_save                   (VipsImage *in,
                                                         const char *filename,
                                                         ...);

Saves in to filename using the saver recommended by vips_foreign_find_save(). Options are not in filename but must be given as a NULL-terminated list of name-value pairs.

See also: vips_foreign_load().

vips_foreign_save_options ()

int                 vips_foreign_save_options           (VipsImage *in,
                                                         const char *filename);

Saves in to filename using the saver recommended by vips_foreign_find_save().

Arguments to the saver may be embedded in the filename using the usual syntax.

See also: vips_foreign_save().

vips_jpegload ()

int                 vips_jpegload                       (const char *filename,
                                                         VipsImage **out,
                                                         ...);

Optional arguments:

shrink: shrink by this much on load fail: fail on warnings

Read a JPEG file into a VIPS image. It can read most 8-bit JPEG images, including CMYK and YCbCr.

shrink means shrink by this integer factor during load. Possible values are 1, 2, 4 and 8. Shrinking during read is very much faster than decompressing the whole image and then shrinking later.

Setting fail to true makes the JPEG reader fail on any warnings. This can be useful for detecting truncated files, for example. Normally reading these produces a warning, but no fatal error.

Example:

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vips_jpegload( "fred.jpg", &out,
    "shrink", 8,
    "fail", TRUE,
    NULL );

Any embedded ICC profiles are ignored: you always just get the RGB from the file. Instead, the embedded profile will be attached to the image as metadata. You need to use something like im_icc_import() to get CIE values from the file. Any EXIF data is also attached as VIPS metadata.

The int metadata item "jpeg-multiscan" is set to the result of jpeg_has_multiple_scans(). Interlaced jpeg images need a large amount of memory to load, so this field gives callers a chance to handle these images differently.

The EXIF thumbnail, if present, is attached to the image as "jpeg-thumbnail-data". See vips_image_get_blob().

This function only reads the image header and does not decompress any pixel data. Decompression only occurs when pixels are accessed by some other function.

See also: vips_jpegload_buffer(), vips_image_new_from_file().

vips_jpegload_buffer ()

int                 vips_jpegload_buffer                (void *buf,
                                                         size_t len,
                                                         VipsImage **out,
                                                         ...);

Read a JPEG-formatted memory block into a VIPS image. It can read most 8-bit JPEG images, including CMYK and YCbCr.

This function is handy for processing JPEG image thumbnails.

Caution: on return only the header will have been read, the pixel data is not decompressed until the first pixel is read. Therefore you must not free buf until you have read pixel data from out.

See also: vips_jpegload().

vips_jpegsave ()

int                 vips_jpegsave                       (VipsImage *in,
                                                         const char *filename,
                                                         ...);

Optional arguments:

Q: quality factor profile: attach this ICC profile

Write a VIPS image to a file as JPEG.

Use Q to set the JPEG compression factor. Default 75.

Use profile to give the filename of a profile to be em,bedded in the JPEG. This does not affect the pixels which are written, just the way they are tagged. You can use the special string "none" to mean "don't attach a profile".

If no profile is specified and the VIPS header contains an ICC profile named VIPS_META_ICC_NAME ("icc-profile-data"), the profile from the VIPS header will be attached.

The image is automatically converted to RGB, Monochrome or CMYK before saving. Any metadata attached to the image is saved as EXIF, if possible.

See also: vips_jpegsave_buffer(), vips_image_write_file().

vips_jpegsave_buffer ()

int                 vips_jpegsave_buffer                (VipsImage *in,
                                                         void **buf,
                                                         size_t *len,
                                                         ...);

Optional arguments:

Q: JPEG quality factor profile: attach this ICC profile

As vips_jpegsave(), but save to a memory buffer.

The address of the buffer is returned in obuf, the length of the buffer in olen. You are responsible for freeing the buffer with g_free() when you are done with it.

See also: vips_jpegsave(), vips_image_write_to_file().

vips_jpegsave_mime ()

int                 vips_jpegsave_mime                  (VipsImage *in,
                                                         ...);

Optional arguments:

Q: JPEG quality factor profile: attach this ICC profile

As vips_jpegsave(), but save as a mime jpeg on stdout.

See also: vips_jpegsave(), vips_image_write_to_file().

vips_magickload ()

int                 vips_magickload                     (const char *filename,
                                                         VipsImage **out,
                                                         ...);

Read in an image using libMagick, the ImageMagick library. This library can read more than 80 file formats, including SVG, BMP, EPS, DICOM and many others. The reader can handle any ImageMagick image, including the float and double formats. It will work with any quantum size, including HDR. Any metadata attached to the libMagick image is copied on to the VIPS image.

The reader should also work with most versions of GraphicsMagick. See the "--with-magickpackage" configure option.

See also: vips_image_new_from_file().

vips_matload ()

int                 vips_matload                        (const char *filename,
                                                         VipsImage **out,
                                                         ...);

Read a Matlab save file into a VIPS image.

This operation searches the save file for the first array variable with between 1 and 3 dimensions and loads it as an image. It will not handle complex images. It does not handle sparse matrices.

See also: vips_image_new_from_file().

vips_openexrload ()

int                 vips_openexrload                    (const char *filename,
                                                         VipsImage **out,
                                                         ...);

Read a OpenEXR file into a VIPS image.

The reader can handle scanline and tiled OpenEXR images. It can't handle OpenEXR colour management, image attributes, many pixel formats, anything other than RGBA.

This reader uses the rather limited OpenEXR C API. It should really be redone in C++.

See also: vips_image_new_from_file().

vips_openslideload ()

int                 vips_openslideload                  (const char *filename,
                                                         VipsImage **out,
                                                         ...);

Optional arguments:

layer: load this layer associated: load this associated image

Read a virtual slide supported by the OpenSlide library into a VIPS image. OpenSlide supports images in Aperio, Hamamatsu VMS, Hamamatsu VMU, MIRAX, and Trestle formats.

To facilitate zooming, virtual slide formats include multiple scaled-down versions of the high-resolution image. These are typically called "levels", though OpenSlide and im_openslide2vips() call them "layers". By default, vips_openslideload() reads the highest-resolution layer (layer 0). Set layer to the layer number you want.

In addition to the slide image itself, virtual slide formats sometimes include additional images, such as a scan of the slide's barcode. OpenSlide calls these "associated images". To read an associated image, set associated to the image's name. A slide's associated images are listed in the "slide-associated-images" metadata item.

The output of this operator is in pre-multipled ARGB format. Use im_argb2rgba() to decode to png-style RGBA.

See also: vips_image_new_from_file().

vips_pngload ()

int                 vips_pngload                        (const char *filename,
                                                         VipsImage **out,
                                                         ...);

Optional arguments:

sequential: sequential read only

Read a PNG file into a VIPS image. It can read all png images, including 8- and 16-bit images, 1 and 3 channel, with and without an alpha channel.

Setting sequential to TRUE means you promise to only demand tiles from this image top-top-bottom, ie. to read sequentially. This means the png loader can read directly from the image without having to generate a random-access intermediate. This can save a lot of time and memory for large images, but limits the sorts of operation you can perform. It's useful for things like generating thumbnails.

There is no support for embedded ICC profiles.

See also: vips_image_new_from_file().

vips_pngsave ()

int                 vips_pngsave                        (VipsImage *in,
                                                         const char *filename,
                                                         ...);

Optional arguments:

compression: compression level interlace: interlace image

Write a VIPS image to a file as PNG.

compression means compress with this much effort (0 - 9). Default 6.

Set interlace to TRUE to interlace the image with ADAM7 interlacing. Beware than an interlaced PNG can be up to 7 times slower to write than a non-interlaced image.

There is no support for attaching ICC profiles to PNG images.

The image is automatically converted to RGB, RGBA, Monochrome or Mono + alpha before saving. Images with more than one byte per band element are saved as 16-bit PNG, others are saved as 8-bit PNG.

See also: vips_image_new_from_file().

vips_pngsave_buffer ()

int                 vips_pngsave_buffer                 (VipsImage *in,
                                                         void **buf,
                                                         size_t *len,
                                                         ...);

Optional arguments:

compression: compression level interlace: interlace image

As vips_pngsave(), but save to a memory buffer.

The address of the buffer is returned in obuf, the length of the buffer in olen. You are responsible for freeing the buffer with g_free() when you are done with it.

See also: vips_pngsave(), vips_image_write_to_file().

vips_ppmload ()

int                 vips_ppmload                        (const char *filename,
                                                         VipsImage **out,
                                                         ...);

Read a PPM/PBM/PGM/PFM file into a VIPS image.

It can read 1, 8, 16 and 32 bit images, colour or monochrome, stored in binary or in ASCII. One bit images become 8 bit VIPS images, with 0 and 255 for 0 and 1.

See also: vips_image_new_from_file().

vips_ppmsave ()

int                 vips_ppmsave                        (VipsImage *in,
                                                         const char *filename,
                                                         ...);

Optional arguments:

ascii: save as ASCII rather than binary

Write a VIPS image to a file as PPM. It can write 8, 16 or 32 bit unsigned integer images, float images, colour or monochrome, stored as binary or ASCII. Integer images of more than 8 bits can only be stored in ASCII.

When writing float (PFM) images the scale factor is set from the "pfm-scale" metadata.

Set ascii to TRUE to write as human-readable ASCII. Normally data is written in binary.

The storage format is indicated by a filename extension. Use one of .pbm, .pgm, .ppm, .pfm.

See also: vips_image_write_file().

vips_radload ()

int                 vips_radload                        (const char *filename,
                                                         VipsImage **out,
                                                         ...);

Read a Radiance (HDR) file into a VIPS image.

Radiance files are read as VIPS_CODING_RAD. They have one byte for each of red, green and blue, and one byte of shared exponent. Some operations (like vips_extract_area()) can work directly with images in this format, but mmany (all the arithmetic operations, for example) will not. Unpack VIPS_CODING_RAD images to 3 band float with im_rad2float() if you want to do arithmetic on them.

This operation ignores some header fields, like VIEW and DATE. It will not rotate/flip as the FORMAT string asks.

Sections of this reader from Greg Ward and Radiance with kind permission.

See also: vips_image_new_from_file().

vips_radsave ()

int                 vips_radsave                        (VipsImage *in,
                                                         const char *filename,
                                                         ...);

Write a VIPS image in Radiance (HDR) format.

Sections of this reader from Greg Ward and Radiance with kind permission.

See also: vips_image_write_file().

vips_rawload ()

int                 vips_rawload                        (const char *filename,
                                                         VipsImage **out,
                                                         int width,
                                                         int height,
                                                         int bands,
                                                         ...);

Optional arguments:

width: width of image in pixels height: height of image in pixels bands: number of image bands offset: offset in bytes from start of file

This operation mmaps the file, setting out so that access to that image will read from the file.

Use functions like vips_copy() to set the pixel type, byte ordering and so on.

See also: vips_image_new_from_file().

vips_rawsave ()

int                 vips_rawsave                        (VipsImage *in,
                                                         const char *filename,
                                                         ...);

Writes the pixels in in to the file filename with no header or other metadata.

See also: vips_image_write_file().

vips_rawsave_fd ()

int                 vips_rawsave_fd                     (VipsImage *in,
                                                         int fd,
                                                         ...);

Writes the pixels in in to the fd with no header or other metadata. Handy for implementing other savers.

See also: vips_rawsave().

vips_tiffload ()

int                 vips_tiffload                       (const char *filename,
                                                         VipsImage **out,
                                                         ...);

Optional arguments:

page: load this page

Read a TIFF file into a VIPS image. It is a full baseline TIFF 6 reader, with extensions for tiled images, multipage images, LAB colour space, pyramidal images and JPEG compression. including CMYK and YCbCr.

page means load this page from the file. By default the first page (page 0) is read.

Any ICC profile is read and attached to the VIPS image.

See also: vips_image_new_from_file().

vips_tiffsave ()

int                 vips_tiffsave                       (VipsImage *in,
                                                         const char *filename,
                                                         ...);

Optional arguments:

compression; use this compression scheme Q: quality factor predictor; compress with this prediction profile: attach this ICC profile tile; set TRUE to write a tiled tiff tile_width; set tile size tile_height; set tile size pyramid; set TRUE to write an image pyramid squash; squash 8-bit images down to 1 bit resunit; use pixels per inch or cm for the resolution xres; horizontal resolution yres; vertical resolution bigtiff; write a BigTiff file

Write a VIPS image to a file as TIFF.

Use compression to set the tiff compression. Currently jpeg, packbits, fax4, lzw, none and deflate are supported. The default is no compression. JPEG compression is a good lossy compressor for photographs, packbits is good for 1-bit images, and deflate is the best lossless compression TIFF can do. LZW has patent problems and is no longer recommended.

Use Q to set the JPEG compression factor. Default 75.

Use predictor to set the predictor for lzw and deflate compression.

Predictor is not set by default. There are three predictor values recognised at the moment (2007, July): 1 is no prediction, 2 is a horizontal differencing and 3 is a floating point predictor. Refer to the libtiff specifications for further discussion of various predictors. In short, predictor helps to better compress image, especially in case of digital photos or scanned images and bit depths > 8. Try it to find whether it works for your images.

Use profile to give the filename of a profile to be embedded in the TIFF. This does not affect the pixels which are written, just the way they are tagged. You can use the special string "none" to mean "don't attach a profile".

If no profile is specified and the VIPS header contains an ICC profile named VIPS_META_ICC_NAME ("icc-profile-data"), the profile from the VIPS header will be attached.

Set tile to TRUE to write a tiled tiff. By default tiff are written in strips. Use tile_width and tile_height to set the tile size. The defaiult is 128 by 128.

Set pyramid to write the image as a set of images, one per page, of decreasing size.

Set squash to make 8-bit uchar images write as 1-bit TIFFs with zero pixels written as 0 and non-zero as 1.

Use resunit to override the default resolution unit. The default resolution unit is taken from the header field "resolution-unit" (VIPS_META_RESOLUTION_UNIT in C). If this field is not set, then VIPS defaults to cm.

Use xres and yres to override the default horizontal and vertical resolutions. By default these values are taken from the VIPS image header.

Set bigtiff to attempt to write a bigtiff. Bigtiff is a variant of the TIFF format that allows more than 4GB in a file.

See also: vips_tiffload(), vips_image_write_file().

The "disc" property

  "disc"                     gboolean              : Read / Write

Open to disc.

Default value: TRUE

The "flags" property

  "flags"                    VipsForeignFlags      : Read / Write

Flags for this file.

The "out" property

  "out"                      VipsImage*            : Read / Write

Output image.

The "sequential" property

  "sequential"               gboolean              : Read / Write

Sequential read only.

Default value: FALSE

The "in" property

  "in"                       VipsImage*            : Read / Write

Image to save.