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basic

basic — a few typedefs used everywhere

Stability Level

Stable, unless otherwise indicated

Functions

int (*VipsCallbackFn) ()
void * (*VipsSListMap2Fn) ()
void * (*VipsSListMap4Fn) ()
void * (*VipsSListFold2Fn) ()
char * vips_path_filename7 ()
char * vips_path_mode7 ()

Properties

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

Signals

void eval Run Last
void invalidate Action
void minimise Action
void posteval Run Last
void preeval Run Last
void written Action

Types and Values

Object Hierarchy

    GObject
    ╰── VipsObject
        ├── VipsImage
        ╰── VipsRegion

Includes

#include <vips/vips.h>

Description

A few simple typedefs used by VIPS.

Functions

VipsCallbackFn ()

int
(*VipsCallbackFn) (void *a,
                   void *b);

VipsSListMap2Fn ()

void *
(*VipsSListMap2Fn) (void *item,
                    void *a,
                    void *b);

VipsSListMap4Fn ()

void *
(*VipsSListMap4Fn) (void *item,
                    void *a,
                    void *b,
                    void *c,
                    void *d);

VipsSListFold2Fn ()

void *
(*VipsSListFold2Fn) (void *item,
                     void *a,
                     void *b,
                     void *c);

vips_path_filename7 ()

char *
vips_path_filename7 (const char *path);

Return the filename part of a vips7 path. For testing only.

Parameters

path

path to split

 

vips_path_mode7 ()

char *
vips_path_mode7 (const char *path);

Return the mode part of a vips7 path. For testing only.

Parameters

path

path to split

 

Types and Values

VipsPel

typedef unsigned char VipsPel;

A picture element. Cast this to whatever the associated VipsBandFormat says to get the value.


enum VipsPrecision

How accurate an operation should be.

Members

VIPS_PRECISION_INTEGER

int everywhere

 

VIPS_PRECISION_FLOAT

float everywhere

 

VIPS_PRECISION_APPROXIMATE

approximate integer output

 

VIPS_PRECISION_LAST

   

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.


VipsRegion

typedef struct {
	/* Users may read these two fields.
	 */
	VipsImage *im;		/* Link back to parent image */
	VipsRect valid;		/* Area of parent we can see */

	/* The rest of VipsRegion is private.
	 */
} VipsRegion;

A small part of a VipsImage. valid holds the left/top/width/height of the area of pixels that are available from the region.

See also: VIPS_REGION_ADDR(), vips_region_new(), vips_region_prepare().

Members

VipsImage *im;

the VipsImage that this region is defined on

 

VipsRect valid;

the VipsRect of pixels that this region represents

 

Property Details

The “bands” property

  “bands”                    gint

Number of bands in image.

Owner: VipsImage

Flags: Read / Write

Allowed values: [1,10000000]

Default value: 1


The “coding” property

  “coding”                   VipsCoding

Pixel coding.

Owner: VipsImage

Flags: Read / Write

Default value: VIPS_CODING_NONE


The “demand” property

  “demand”                   VipsDemandStyle

Preferred demand style for this image.

Owner: VipsImage

Flags: Read / Write

Default value: VIPS_DEMAND_STYLE_SMALLTILE


The “filename” property

  “filename”                 gchar *

Image filename.

Owner: VipsImage

Flags: Read / Write

Default value: NULL


The “foreign-buffer” property

  “foreign-buffer”           gpointer

Pointer to foreign pixels.

Owner: VipsImage

Flags: Read / Write


The “format” property

  “format”                   VipsBandFormat

Pixel format in image.

Owner: VipsImage

Flags: Read / Write

Default value: VIPS_FORMAT_UCHAR


The “height” property

  “height”                   gint

Image height in pixels.

Owner: VipsImage

Flags: Read / Write

Allowed values: [1,10000000]

Default value: 1


The “interpretation” property

  “interpretation”           VipsInterpretation

Pixel interpretation.

Owner: VipsImage

Flags: Read / Write

Default value: VIPS_INTERPRETATION_MULTIBAND


The “kill” property

  “kill”                     gboolean

Block evaluation on this image.

Owner: VipsImage

Flags: Read / Write

Default value: FALSE


The “mode” property

  “mode”                     gchar *

Open mode.

Owner: VipsImage

Flags: Read / Write

Default value: "p"


The “sizeof-header” property

  “sizeof-header”            guint64

Offset in bytes from start of file.

Owner: VipsImage

Flags: Read / Write

Allowed values: <= 1000000000

Default value: 64


The “width” property

  “width”                    gint

Image width in pixels.

Owner: VipsImage

Flags: Read / Write

Allowed values: [1,10000000]

Default value: 1


The “xoffset” property

  “xoffset”                  gint

Horizontal offset of origin.

Owner: VipsImage

Flags: Read / Write

Allowed values: [-10000000,10000000]

Default value: 0


The “xres” property

  “xres”                     gdouble

Horizontal resolution in pixels/mm.

Owner: VipsImage

Flags: Read / Write

Allowed values: [-0,1e+06]

Default value: 0


The “yoffset” property

  “yoffset”                  gint

Vertical offset of origin.

Owner: VipsImage

Flags: Read / Write

Allowed values: [-10000000,10000000]

Default value: 0


The “yres” property

  “yres”                     gdouble

Vertical resolution in pixels/mm.

Owner: VipsImage

Flags: Read / Write

Allowed values: [-0,1e+06]

Default value: 0

Signal Details

The “eval” signal

void
user_function (VipsImage *image,
               gpointer   progress,
               gpointer   user_data)

The ::eval signal is emitted once per work unit (typically a 128 x 128 area of pixels) during image computation.

You can use this signal to update user-interfaces with progress feedback. Beware of updating too frequently: you will usually need some throttling mechanism.

Use vips_image_set_progress() to turn on progress reporting for an image.

Parameters

image

the image being calculated

 

progress

VipsProgress for this image

 

user_data

user data set when the signal handler was connected.

 

Flags: Run Last


The “invalidate” signal

void
user_function (VipsImage *image,
               gpointer   user_data)

The ::invalidate signal is emitted when an image or one of it's upstream data sources has been destructively modified. See vips_image_invalidate_all().

Parameters

image

the image that has changed

 

user_data

user data set when the signal handler was connected.

 

Flags: Action


The “minimise” signal

void
user_function (VipsImage *image,
               gpointer   user_data)

The ::minimise signal is emitted when an image has been asked to minimise memory usage. All non-essential caches are dropped. See vips_image_minimise_all().

Parameters

image

the image that is being minimised

 

user_data

user data set when the signal handler was connected.

 

Flags: Action


The “posteval” signal

void
user_function (VipsImage *image,
               gpointer   progress,
               gpointer   user_data)

The ::posteval signal is emitted once at the end of the computation of image . It's a good place to shut down evaluation feedback.

Use vips_image_set_progress() to turn on progress reporting for an image.

Parameters

image

the image that was calculated

 

progress

VipsProgress for this image

 

user_data

user data set when the signal handler was connected.

 

Flags: Run Last


The “preeval” signal

void
user_function (VipsImage *image,
               gpointer   progress,
               gpointer   user_data)

The ::preeval signal is emitted once before computation of image starts. It's a good place to set up evaluation feedback.

Use vips_image_set_progress() to turn on progress reporting for an image.

Parameters

image

the image to be calculated

 

progress

VipsProgress for this image

 

user_data

user data set when the signal handler was connected.

 

Flags: Run Last


The “written” signal

void
user_function (VipsImage *image,
               gpointer   result,
               gpointer   user_data)

The ::written signal is emitted just after an image has been written to. It is used by vips to implement things like write to foreign file formats.

Parameters

image

the image that was calculated

 

result

set to non-zero to indicate error

 

user_data

user data set when the signal handler was connected.

 

Flags: Action

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