VipsImage

VipsImage — the VIPS image class

Stability Level

Stable, unless otherwise indicated

Synopsis

#include <vips/vips.h>

#define             VIPS_MAGIC_INTEL
#define             VIPS_MAGIC_SPARC
enum                VipsDemandStyle;
enum                VipsImageType;
enum                VipsInterpretation;
enum                VipsBandFormat;
enum                VipsCoding;
enum                VipsAccess;
                    VipsProgress;
                    VipsImage;
                    VipsImageClass;
#define             VIPS_IMAGE_SIZEOF_ELEMENT           (I)
#define             VIPS_IMAGE_SIZEOF_PEL               (I)
#define             VIPS_IMAGE_SIZEOF_LINE              (I)
#define             VIPS_IMAGE_N_ELEMENTS               (I)
#define             VIPS_IMAGE_N_PELS                   (I)
#define             VIPS_IMAGE_ADDR                     (I,
                                                         X,
                                                         Y)
#define             VIPS_MATRIX                         (I,
                                                         X,
                                                         Y)
int                 vips_image_written                  (VipsImage *image);
void                vips_image_invalidate_all           (VipsImage *image);
void                vips_image_minimise_all             (VipsImage *image);
void                vips_image_preeval                  (VipsImage *image);
void                vips_image_eval                     (VipsImage *image,
                                                         guint64 processed);
void                vips_image_posteval                 (VipsImage *image);
void                vips_image_set_progress             (VipsImage *image,
                                                         gboolean progress);
gboolean            vips_image_iskilled                 (VipsImage *image);
void                vips_image_set_kill                 (VipsImage *image,
                                                         gboolean kill);
VipsImage *         vips_image_new                      (void);
VipsImage *         vips_image_new_mode                 (const char *filename,
                                                         const char *mode);
VipsImage *         vips_image_new_buffer               (void);
VipsImage *         vips_image_new_from_file            (const char *filename);
VipsImage *         vips_image_new_from_file_raw        (const char *filename,
                                                         int xsize,
                                                         int ysize,
                                                         int bands,
                                                         guint64 offset);
VipsImage *         vips_image_new_from_memory          (void *buffer,
                                                         int xsize,
                                                         int ysize,
                                                         int bands,
                                                         VipsBandFormat bandfmt);
VipsImage *         vips_image_new_matrix               (int width,
                                                         int height);
VipsImage *         vips_image_new_matrixv              (int width,
                                                         int height,
                                                         ...);
void                vips_image_set_delete_on_close      (VipsImage *image,
                                                         gboolean delete_on_close);
VipsImage *         vips_image_new_temp_file            (const char *format);
int                 vips_image_write                    (VipsImage *image,
                                                         VipsImage *out);
int                 vips_image_write_to_file            (VipsImage *image,
                                                         const char *filename);
gboolean            vips_image_isMSBfirst               (VipsImage *image);
gboolean            vips_image_isfile                   (VipsImage *image);
gboolean            vips_image_ispartial                (VipsImage *image);
int                 vips_image_wio_input                (VipsImage *image);
int                 vips_image_pio_input                (VipsImage *image);
int                 vips_image_inplace                  (VipsImage *image);
int                 vips_image_write_prepare            (VipsImage *image);
int                 vips_image_write_line               (VipsImage *image,
                                                         int ypos,
                                                         VipsPel *linebuffer);
gboolean            vips_band_format_isint              (VipsBandFormat format);
gboolean            vips_band_format_isuint             (VipsBandFormat format);
gboolean            vips_band_format_is8bit             (VipsBandFormat format);
gboolean            vips_band_format_isfloat            (VipsBandFormat format);
gboolean            vips_band_format_iscomplex          (VipsBandFormat format);
int                 vips_system                         (const char *cmd_format,
                                                         ...);

Object Hierarchy

  GObject
   +----VipsObject
         +----VipsImage

Properties

  "bands"                    gint                  : Read / Write
  "coding"                   VipsCoding            : Read / Write
  "demand"                   VipsDemandStyle       : Read / Write
  "filename"                 gchar*                : Read / Write
  "foreign-buffer"           gpointer              : Read / Write
  "format"                   VipsBandFormat        : Read / Write
  "height"                   gint                  : Read / Write
  "interpretation"           VipsInterpretation    : Read / Write
  "kill"                     gboolean              : Read / Write
  "mode"                     gchar*                : Read / Write
  "sizeof-header"            guint64               : Read / Write
  "width"                    gint                  : Read / Write
  "xoffset"                  gint                  : Read / Write
  "xres"                     gdouble               : Read / Write
  "yoffset"                  gint                  : Read / Write
  "yres"                     gdouble               : Read / Write

Signals

  "eval"                                           : Run Last
  "invalidate"                                     : Action
  "minimise"                                       : Action
  "posteval"                                       : Run Last
  "preeval"                                        : Run Last
  "written"                                        : Action

Description

The image class and associated types and macros.

vips_image_wio_input() and friends indicate the image IO style you intend to use, transforming the underlying VipsImage structure if necessary.

Details

VIPS_MAGIC_INTEL

#define VIPS_MAGIC_INTEL (0xb6a6f208U)

The first four bytes of a VIPS file in Intel byte ordering.


VIPS_MAGIC_SPARC

#define VIPS_MAGIC_SPARC (0x08f2a6b6U)

The first four bytes of a VIPS file in SPARC byte ordering.


enum VipsDemandStyle

typedef enum {
	VIPS_DEMAND_STYLE_ERROR = -1,	
	VIPS_DEMAND_STYLE_SMALLTILE,	
	VIPS_DEMAND_STYLE_FATSTRIP,
	VIPS_DEMAND_STYLE_THINSTRIP,
	VIPS_DEMAND_STYLE_ANY			
} VipsDemandStyle;

See vips_demand_hint(). Operations can hint to the VIPS image IO system about the kind of demand geometry they prefer.

These demand styles are given below in order of increasing restrictiveness. When demanding output from a pipeline, vips_image_generate() will use the most restrictive of the styles requested by the operations in the pipeline.

VIPS_DEMAND_STYLE_THINSTRIP --- This operation would like to output strips the width of the image and a few pels high. This is option suitable for point-to-point operations, such as those in the arithmetic package.

This option is only efficient for cases where each output pel depends upon the pel in the corresponding position in the input image.

VIPS_DEMAND_STYLE_FATSTRIP --- This operation would like to output strips the width of the image and as high as possible. This option is suitable for area operations which do not violently transform coordinates, such as im_conv().

VIPS_DEMAND_STYLE_SMALLTILE --- This is the most general demand format. Output is demanded in small (around 100x100 pel) sections. This style works reasonably efficiently, even for bizzare operations like 45 degree rotate.

VIPS_DEMAND_STYLE_ANY --- This image is not being demand-read from a disc file (even indirectly) so any demand style is OK. It's used for things like im_black() where the pixels are calculated.

See also: vips_demand_hint().

VIPS_DEMAND_STYLE_ERROR

VIPS_DEMAND_STYLE_SMALLTILE

demand in small (typically 64x64 pixel) tiles

VIPS_DEMAND_STYLE_FATSTRIP

demand in fat (typically 10 pixel high) strips

VIPS_DEMAND_STYLE_THINSTRIP

demand in thin (typically 1 pixel high) strips

VIPS_DEMAND_STYLE_ANY

demand geometry does not matter

enum VipsImageType

typedef enum {
	VIPS_IMAGE_ERROR = -1,	
	VIPS_IMAGE_NONE,		/* no type set */
	VIPS_IMAGE_SETBUF,		/* malloced memory array */
	VIPS_IMAGE_SETBUF_FOREIGN, /* memory array, don't free on close */
	VIPS_IMAGE_OPENIN,		/* input from fd with a window */
	VIPS_IMAGE_MMAPIN,		/* memory mapped input file */
	VIPS_IMAGE_MMAPINRW,		/* memory mapped read/write file */
	VIPS_IMAGE_OPENOUT,		/* output to fd */
	VIPS_IMAGE_PARTIAL		/* partial image */
} VipsImageType;

VIPS_IMAGE_ERROR

VIPS_IMAGE_NONE

VIPS_IMAGE_SETBUF

VIPS_IMAGE_SETBUF_FOREIGN

VIPS_IMAGE_OPENIN

VIPS_IMAGE_MMAPIN

VIPS_IMAGE_MMAPINRW

VIPS_IMAGE_OPENOUT

VIPS_IMAGE_PARTIAL


enum VipsInterpretation

typedef enum {
	VIPS_INTERPRETATION_ERROR = -1,
	VIPS_INTERPRETATION_MULTIBAND = 0,
	VIPS_INTERPRETATION_B_W = 1,
	VIPS_INTERPRETATION_HISTOGRAM = 10,
	VIPS_INTERPRETATION_XYZ = 12,
	VIPS_INTERPRETATION_LAB = 13,
	VIPS_INTERPRETATION_CMYK = 15,
	VIPS_INTERPRETATION_LABQ = 16,
	VIPS_INTERPRETATION_RGB = 17,
	VIPS_INTERPRETATION_CMC = 18,
	VIPS_INTERPRETATION_LCH = 19,
	VIPS_INTERPRETATION_LABS = 21,
	VIPS_INTERPRETATION_sRGB = 22,
	VIPS_INTERPRETATION_YXY = 23,
	VIPS_INTERPRETATION_FOURIER = 24,
	VIPS_INTERPRETATION_RGB16 = 25,
	VIPS_INTERPRETATION_GREY16 = 26,
	VIPS_INTERPRETATION_MATRIX = 27,
	VIPS_INTERPRETATION_scRGB = 28
} VipsInterpretation;

How the values in an image should be interpreted. For example, a three-band float image of type VIPS_INTERPRETATION_LAB should have its pixels interpreted as coordinates in CIE Lab space.

These values are set by operations as hints to user-interfaces built on top of VIPS to help them show images to the user in a meaningful way. Operations do not use these values to decide their action.

The gaps in the numbering are historical and must be maintained. Allocate new numbers from the end.

VIPS_INTERPRETATION_ERROR

VIPS_INTERPRETATION_MULTIBAND

generic many-band image

VIPS_INTERPRETATION_B_W

some kind of single-band image

VIPS_INTERPRETATION_HISTOGRAM

a 1D image, eg. histogram or lookup table

VIPS_INTERPRETATION_XYZ

the first three bands are CIE XYZ

VIPS_INTERPRETATION_LAB

pixels are in CIE Lab space

VIPS_INTERPRETATION_CMYK

the first four bands are in CMYK space

VIPS_INTERPRETATION_LABQ

implies VIPS_CODING_LABQ

VIPS_INTERPRETATION_RGB

generic RGB space

VIPS_INTERPRETATION_CMC

a uniform colourspace based on CMC(1:1)

VIPS_INTERPRETATION_LCH

pixels are in CIE LCh space

VIPS_INTERPRETATION_LABS

CIE LAB coded as three signed 16-bit values

VIPS_INTERPRETATION_sRGB

pixels are sRGB

VIPS_INTERPRETATION_YXY

pixels are CIE Yxy

VIPS_INTERPRETATION_FOURIER

image is in fourier space

VIPS_INTERPRETATION_RGB16

generic 16-bit RGB

VIPS_INTERPRETATION_GREY16

generic 16-bit mono

VIPS_INTERPRETATION_MATRIX

a matrix

VIPS_INTERPRETATION_scRGB

pixels are scRGB

enum VipsBandFormat

typedef enum {
	VIPS_FORMAT_NOTSET = -1,
	VIPS_FORMAT_UCHAR = 0,
	VIPS_FORMAT_CHAR = 1,
	VIPS_FORMAT_USHORT = 2,
	VIPS_FORMAT_SHORT = 3,
	VIPS_FORMAT_UINT = 4,
	VIPS_FORMAT_INT = 5,
	VIPS_FORMAT_FLOAT = 6,
	VIPS_FORMAT_COMPLEX = 7,
	VIPS_FORMAT_DOUBLE = 8,
	VIPS_FORMAT_DPCOMPLEX = 9,
	VIPS_FORMAT_LAST = 10
} VipsBandFormat;

The format used for each band element.

Each corresponnds to a native C type for the current machine. For example, VIPS_FORMAT_USHORT is unsigned short.

VIPS_FORMAT_NOTSET

invalid setting

VIPS_FORMAT_UCHAR

unsigned char format

VIPS_FORMAT_CHAR

char format

VIPS_FORMAT_USHORT

unsigned short format

VIPS_FORMAT_SHORT

short format

VIPS_FORMAT_UINT

unsigned int format

VIPS_FORMAT_INT

int format

VIPS_FORMAT_FLOAT

float format

VIPS_FORMAT_COMPLEX

complex (two floats) format

VIPS_FORMAT_DOUBLE

double float format

VIPS_FORMAT_DPCOMPLEX

double complex (two double) format

VIPS_FORMAT_LAST


enum VipsCoding

typedef enum {
	VIPS_CODING_ERROR = -1,
	VIPS_CODING_NONE = 0,
	VIPS_CODING_LABQ = 2,
	VIPS_CODING_RAD = 6,
	VIPS_CODING_LAST = 7
} VipsCoding;

How pixels are coded.

Normally, pixels are uncoded and can be manipulated as you would expect. However some file formats code pixels for compression, and sometimes it's useful to be able to manipulate images in the coded format.

The gaps in the numbering are historical and must be maintained. Allocate new numbers from the end.

VIPS_CODING_ERROR

VIPS_CODING_NONE

pixels are not coded

VIPS_CODING_LABQ

pixels encode 3 float CIELAB values as 4 uchar

VIPS_CODING_RAD

pixels encode 3 float RGB as 4 uchar (Radiance coding)

VIPS_CODING_LAST


enum VipsAccess

typedef enum {
	VIPS_ACCESS_RANDOM,
	VIPS_ACCESS_SEQUENTIAL,
	VIPS_ACCESS_SEQUENTIAL_UNBUFFERED,
	VIPS_ACCESS_LAST
} VipsAccess;

The type of access an operation has to supply. See vips_tilecache() and VipsForeign.

VIPS_ACCESS_RANDOM means requests can come in any order.

VIPS_ACCESS_SEQUENTIAL means requests will be top-to-bottom, but with some amount of buffering behind the read point for small non-local accesses.

VIPS_ACCESS_SEQUENTIAL_UNBUFFERED means requests will be strictly top-to-bottom with no read-behind. This can save some memory.

VIPS_ACCESS_RANDOM

can read anywhere

VIPS_ACCESS_SEQUENTIAL

top-to-bottom reading only, but with a small buffer

VIPS_ACCESS_SEQUENTIAL_UNBUFFERED

top-to-bottom reading only

VIPS_ACCESS_LAST


VipsProgress

typedef struct {
	int run;		/* Time we have been running */
	int eta;		/* Estimated seconds of computation left */
	gint64 tpels;		/* Number of pels we expect to calculate */
	gint64 npels;		/* Number of pels calculated so far */
	int percent;		/* Percent complete */
	GTimer *start;		/* Start time */
} VipsProgress;

A structure available to eval callbacks giving information on evaluation progress. See "eval".

int run;

Time we have been running

int eta;

Estimated seconds of computation left

gint64 tpels;

Number of pels we expect to calculate

gint64 npels;

Number of pels calculated so far

int percent;

Percent complete

GTimer *start;

Start time

VipsImage

typedef struct _VipsImage VipsImage;

An image. These can represent an image on disc, a memory buffer, an image in the process of being written to disc or a partially evaluated image in memory.


VipsImageClass

typedef struct {
	VipsObjectClass parent_class;

	/* Signals we emit.
	 */

	/* Evaluation is starting.
	 */
	void (*preeval)( VipsImage *image, VipsProgress *progress );

	/* Evaluation progress.
	 */
	void (*eval)( VipsImage *image, VipsProgress *progress );

	/* Evaluation is ending.
	 */
	void (*posteval)( VipsImage *image, VipsProgress *progress );

	/* An image has been written to. 
	 * Used by eg. vips_image_new_mode("x.jpg", "w") to do the 
	 * final write to jpeg.
	 * Set *result to non-zero to indicate an error on write.
	 */
	void (*written)( VipsImage *image, int *result );

	/* An image has been modified in some way and all caches 
	 * need dropping. 
	 */
	void (*invalidate)( VipsImage *image );

	/* Minimise this pipeline. 
	 *
	 * This is triggered (sometimes) at the end of eval to signal that
	 * we're probably done and that operations involved should try to
	 * minimise memory use by, for example, dropping caches. 
	 *
	 * See vips_tilecache().
	 */
	void (*minimise)( VipsImage *image );
} VipsImageClass;


VIPS_IMAGE_SIZEOF_ELEMENT()

#define             VIPS_IMAGE_SIZEOF_ELEMENT( I )

I :

a VipsImage

Returns :

sizeof() a band element.

VIPS_IMAGE_SIZEOF_PEL()

#define             VIPS_IMAGE_SIZEOF_PEL( I )

I :

a VipsImage

Returns :

sizeof() a pixel.

VIPS_IMAGE_SIZEOF_LINE()

#define             VIPS_IMAGE_SIZEOF_LINE( I )

I :

a VipsImage

Returns :

sizeof() a scanline of pixels.

VIPS_IMAGE_N_ELEMENTS()

#define             VIPS_IMAGE_N_ELEMENTS( I )

I :

a VipsImage

Returns :

The number of band elements in a scanline.

VIPS_IMAGE_N_PELS()

#define             VIPS_IMAGE_N_PELS( I )

I :

a VipsImage

Returns :

The number of pels in an image. A 64-bit unsigned int.

VIPS_IMAGE_ADDR()

#define             VIPS_IMAGE_ADDR( I, X, Y )

This macro returns a pointer to a pixel in an image, cast to a VipsPel *. It only works for images which are fully available in memory, so memory buffers and small mapped images only.

If VIPS_DEBUG is defined, you get a version that checks bounds for you.

See also: VIPS_REGION_ADDR().

I :

a VipsImage

X :

x coordinate

Y :

y coordinate

Returns :

The address of pixel (x,y) in the image.

VIPS_MATRIX()

#define             VIPS_MATRIX( I, X, Y )

This macro returns a pointer to a pixel in an image, cast to a double*. The image must have a single band, be VIPS_FORMAT_DOUBLE and be fully available in memory, so memory buffers and small mapped images only.

If VIPS_DEBUG is defined, you get a version that checks bounds and image type for you.

See also: VIPS_IMAGE_ADDR().

I :

a VipsImage

X :

x coordinate

Y :

y coordinate

Returns :

The address of pixel (x,y) in the image.

vips_image_written ()

int                 vips_image_written                  (VipsImage *image);


vips_image_invalidate_all ()

void                vips_image_invalidate_all           (VipsImage *image);

Invalidate all pixel caches on an image and any downstream images, that is, images which depend on this image.

The "invalidate" callback is triggered for all invalidated images.

image :

VipsImage to invalidate

vips_image_minimise_all ()

void                vips_image_minimise_all             (VipsImage *image);

Minimise memory use on this image and any upstream images, that is, images which this image depends upon.

The "minimise" callback is triggered for all minimised images.

image :

VipsImage to minimise

vips_image_preeval ()

void                vips_image_preeval                  (VipsImage *image);


vips_image_eval ()

void                vips_image_eval                     (VipsImage *image,
                                                         guint64 processed);


vips_image_posteval ()

void                vips_image_posteval                 (VipsImage *image);


vips_image_set_progress ()

void                vips_image_set_progress             (VipsImage *image,
                                                         gboolean progress);

vips signals evaluation progress via the "preeval", "eval" and "posteval" signals. Progress is signalled on the most-downstream image for which vips_image_set_progress() was called.

image :

image to signal progress on

progress :

turn progress reporting on or off

vips_image_iskilled ()

gboolean            vips_image_iskilled                 (VipsImage *image);


vips_image_set_kill ()

void                vips_image_set_kill                 (VipsImage *image,
                                                         gboolean kill);


vips_image_new ()

VipsImage *         vips_image_new                      (void);

vips_image_new() creates a "glue" descriptor you can use to join two image processing operations together.

It is the equivalent of vips_image_new_mode("xxx", "p").

Returns :

the new VipsImage, or NULL on error.

vips_image_new_mode ()

VipsImage *         vips_image_new_mode                 (const char *filename,
                                                         const char *mode);

vips_image_new_mode() examines the mode string and creates an appropriate VipsImage.

  • "t" creates a temporary memory buffer image.

  • "p" creates a "glue" descriptor you can use to join operations, see also vips_image_new().

  • "r" opens the named file for reading. If the file is not in the native VIPS format for your machine, vips_image_new_mode() automatically converts the file for you.

    Some formats (eg. tiled tiff) are read directly.

    Some formats (eg. strip tiff) do not support random access and can't be processed directly. Small images are decompressed to memory and loaded from there, large images are decompressed to a disc file and processed from that.

    If the operations you intend to perform are sequential, that is, they operate in a strict top-to-bottom manner, you can use sequential mode instead, see "rs" below, or you can use the lower-level API and control the loading process yourself. See VipsForeign.

    See vips_image_new_temp_file() for an explanation of how VIPS selects a location for the temporary file.

    The disc threshold can be set with the "--vips-disc-threshold" command-line argument, or the IM_DISC_THRESHOLD environment variable. The value is a simple integer, but can take a unit postfix of "k", "m" or "g" to indicate kilobytes, megabytes or gigabytes.

    For example:

    1
    2
    3
    4