GI.GdkPixbuf.Objects.Pixbuf

A pixel buffer.

GdkPixbuf contains information about an image's pixel data, its color space, bits per sample, width and height, and the rowstride (the number of bytes between the start of one row and the start of the next).

Creating new GdkPixbuf

The most basic way to create a pixbuf is to wrap an existing pixel buffer with a Pixbuf instance. You can use the [[e-mail]_from_data] function to do this.

Every time you create a new GdkPixbuf instance for some data, you will need to specify the destroy notification function that will be called when the data buffer needs to be freed; this will happen when a GdkPixbuf is finalized by the reference counting functions. If you have a chunk of static data compiled into your application, you can pass in NULL as the destroy notification function so that the data will not be freed.

The [[e-mail]] constructor function can be used as a convenience to create a pixbuf with an empty buffer; this is equivalent to allocating a data buffer using malloc() and then wrapping it with gdk_pixbuf_new_from_data(). The gdk_pixbuf_new() function will compute an optimal rowstride so that rendering can be performed with an efficient algorithm.

As a special case, you can use the [[e-mail]_from_xpm_data] function to create a pixbuf from inline XPM image data.

You can also copy an existing pixbuf with the [methodpixbuf.copy] function. This is not the same as just acquiring a reference to the old pixbuf instance: the copy function will actually duplicate the pixel data in memory and create a new [classpixbuf] instance for it.

Reference counting

GdkPixbuf structures are reference counted. This means that an application can share a single pixbuf among many parts of the code. When a piece of the program needs to use a pixbuf, it should acquire a reference to it by calling g_object_ref(); when it no longer needs the pixbuf, it should release the reference it acquired by calling g_object_unref(). The resources associated with a GdkPixbuf will be freed when its reference count drops to zero. Newly-created GdkPixbuf instances start with a reference count of one.

Image Data

Image data in a pixbuf is stored in memory in an uncompressed, packed format. Rows in the image are stored top to bottom, and in each row pixels are stored from left to right.

There may be padding at the end of a row.

The "rowstride" value of a pixbuf, as returned by [[e-mail]_rowstride], indicates the number of bytes between rows.

• *NOTE**: If you are copying raw pixbuf data with memcpy() note that the last row in the pixbuf may not be as wide as the full rowstride, but rather just as wide as the pixel data needs to be; that is: it is unsafe to do memcpy (dest, pixels, rowstride * height) to copy a whole pixbuf. Use pixbufCopy instead, or compute the width in bytes of the last row as:

c code

last_row = width * ((n_channels * bits_per_sample + 7) / 8);

The same rule applies when iterating over each row of a GdkPixbuf pixels array.

The following code illustrates a simple put_pixel() function for RGB pixbufs with 8 bits per channel with an alpha channel.

c code

static void
put_pixel (GdkPixbuf *pixbuf,
           int x,
	   int y,
	   guchar red,
	   guchar green,
	   guchar blue,
	   guchar alpha)
{
  int n_channels = gdk_pixbuf_get_n_channels (pixbuf);

  // Ensure that the pixbuf is valid
  g_assert (gdk_pixbuf_get_colorspace (pixbuf) == GDK_COLORSPACE_RGB);
  g_assert (gdk_pixbuf_get_bits_per_sample (pixbuf) == 8);
  g_assert (gdk_pixbuf_get_has_alpha (pixbuf));
  g_assert (n_channels == 4);

  int width = gdk_pixbuf_get_width (pixbuf);
  int height = gdk_pixbuf_get_height (pixbuf);

  // Ensure that the coordinates are in a valid range
  g_assert (x >= 0 && x < width);
  g_assert (y >= 0 && y < height);

  int rowstride = gdk_pixbuf_get_rowstride (pixbuf);

  // The pixel buffer in the GdkPixbuf instance
  guchar *pixels = gdk_pixbuf_get_pixels (pixbuf);

  // The pixel we wish to modify
  guchar *p = pixels + y * rowstride + x * n_channels;
  p[0] = red;
  p[1] = green;
  p[2] = blue;
  p[3] = alpha;
}

Loading images

The GdkPixBuf class provides a simple mechanism for loading an image from a file in synchronous and asynchronous fashion.

For GUI applications, it is recommended to use the asynchronous stream API to avoid blocking the control flow of the application.

Additionally, GdkPixbuf provides the [classgdkPixbuf.PixbufLoader@] API for progressive image loading.

## Saving images

The GdkPixbuf class provides methods for saving image data in a number of file formats. The formatted data can be written to a file or to a memory buffer. @GdkPixbuf` can also call a user-defined callback on the data, which allows to e.g. write the image to a socket or store it in a database.

Exported types

newtype Pixbuf

Memory-managed wrapper type.

Constructors

Pixbuf (ManagedPtr Pixbuf)

Instances

Eq Pixbuf

Defined in GI.GdkPixbuf.Objects.Pixbuf

Methods

(==) :: Pixbuf -> Pixbuf -> Bool

(/=) :: Pixbuf -> Pixbuf -> Bool

GObject Pixbuf

Defined in GI.GdkPixbuf.Objects.Pixbuf

ManagedPtrNewtype Pixbuf

Defined in GI.GdkPixbuf.Objects.Pixbuf

Methods

toManagedPtr :: Pixbuf -> ManagedPtr Pixbuf

TypedObject Pixbuf

Defined in GI.GdkPixbuf.Objects.Pixbuf

Methods

glibType :: IO GType

HasParentTypes Pixbuf

Defined in GI.GdkPixbuf.Objects.Pixbuf

IsGValue (Maybe Pixbuf)

Convert Pixbuf to and from GValue. See toGValue and fromGValue.

Defined in GI.GdkPixbuf.Objects.Pixbuf

Methods

gvalueGType_ :: IO GType

gvalueSet_ :: Ptr GValue -> Maybe Pixbuf -> IO ()

gvalueGet_ :: Ptr GValue -> IO (Maybe Pixbuf)

type ParentTypes Pixbuf

Defined in GI.GdkPixbuf.Objects.Pixbuf

type ParentTypes Pixbuf = '[Object, Icon, LoadableIcon]

class (GObject o, IsDescendantOf Pixbuf o) => IsPixbuf o

Type class for types which can be safely cast to Pixbuf, for instance with toPixbuf.

Instances

(GObject o, IsDescendantOf Pixbuf o) => IsPixbuf o

Defined in GI.GdkPixbuf.Objects.Pixbuf

toPixbuf :: (MonadIO m, IsPixbuf o) => o -> m Pixbuf

Cast to Pixbuf, for types for which this is known to be safe. For general casts, use castTo.

Methods

Click to display all available methods, including inherited ones

Methods

addAlpha, applyEmbeddedOrientation, bindProperty, bindPropertyFull, composite, compositeColor, compositeColorSimple, copy, copyArea, copyOptions, equal, fill, flip, forceFloating, freezeNotify, getv, isFloating, load, loadAsync, loadFinish, newSubpixbuf, notify, notifyByPspec, readPixelBytes, readPixels, ref, refSink, removeOption, rotateSimple, runDispose, saturateAndPixelate, saveToBufferv, saveToCallbackv, saveToStreamv, saveToStreamvAsync, savev, scale, scaleSimple, serialize, stealData, stealQdata, thawNotify, toString, unref, watchClosure.

Getters

getBitsPerSample, getByteLength, getColorspace, getData, getHasAlpha, getHeight, getNChannels, getOption, getOptions, getPixels, getProperty, getQdata, getRowstride, getWidth.

Setters

setData, setDataFull, setOption, setProperty.

addAlpha

pixbufAddAlpha

Arguments

:: (HasCallStack, MonadIO m, IsPixbuf a)

=> a

pixbuf: A Pixbuf.

-> Bool

substituteColor: Whether to set a color to zero opacity.

-> Word8

r: Red value to substitute.

-> Word8

g: Green value to substitute.

-> Word8

b: Blue value to substitute.

-> m Pixbuf

Returns: A newly-created pixbuf

Takes an existing pixbuf and adds an alpha channel to it.

If the existing pixbuf already had an alpha channel, the channel values are copied from the original; otherwise, the alpha channel is initialized to 255 (full opacity).

If substitute_color is TRUE, then the color specified by the (r, g, b) arguments will be assigned zero opacity. That is, if you pass (255, 255, 255) for the substitute color, all white pixels will become fully transparent.

If substitute_color is FALSE, then the (r, g, b) arguments will be ignored.

applyEmbeddedOrientation

pixbufApplyEmbeddedOrientation

Arguments

:: (HasCallStack, MonadIO m, IsPixbuf a)

=> a

src: a pixbuf with an orientation option

-> m (Maybe Pixbuf)

Returns: A newly-created pixbuf

Takes an existing pixbuf and checks for the presence of an associated "orientation" option.

The orientation option may be provided by the JPEG loader (which reads the exif orientation tag) or the TIFF loader (which reads the TIFF orientation tag, and compensates it for the partial transforms performed by libtiff).

If an orientation option/tag is present, the appropriate transform will be performed so that the pixbuf is oriented correctly.

Since: 2.12

calculateRowstride

pixbufCalculateRowstride

Arguments

:: (HasCallStack, MonadIO m)

=> Colorspace

colorspace: Color space for image

-> Bool

hasAlpha: Whether the image should have transparency information

-> Int32

bitsPerSample: Number of bits per color sample

-> Int32

width: Width of image in pixels, must be > 0

-> Int32

height: Height of image in pixels, must be > 0

-> m Int32

Returns: the rowstride for the given values, or -1 in case of error.

Calculates the rowstride that an image created with those values would have.

This function is useful for front-ends and backends that want to check image values without needing to create a GdkPixbuf.

Since: 2.36.8

composite

pixbufComposite

Arguments

:: (HasCallStack, MonadIO m, IsPixbuf a, IsPixbuf b)

=> a

src: a Pixbuf

-> b

dest: the Pixbuf into which to render the results

-> Int32

destX: the left coordinate for region to render

-> Int32

destY: the top coordinate for region to render

-> Int32

destWidth: the width of the region to render

-> Int32

destHeight: the height of the region to render

-> Double

offsetX: the offset in the X direction (currently rounded to an integer)

-> Double

offsetY: the offset in the Y direction (currently rounded to an integer)

-> Double

scaleX: the scale factor in the X direction

-> Double

scaleY: the scale factor in the Y direction

-> InterpType

interpType: the interpolation type for the transformation.

-> Int32

overallAlpha: overall alpha for source image (0..255)

-> m ()

Creates a transformation of the source image src by scaling by scaleX and scaleY then translating by offsetX and offsetY.

This gives an image in the coordinates of the destination pixbuf. The rectangle (destX, destY, destWidth, destHeight) is then alpha blended onto the corresponding rectangle of the original destination image.

When the destination rectangle contains parts not in the source image, the data at the edges of the source image is replicated to infinity.

compositeColor

pixbufCompositeColor

Arguments

:: (HasCallStack, MonadIO m, IsPixbuf a, IsPixbuf b)

=> a

src: a Pixbuf

-> b

dest: the Pixbuf into which to render the results

-> Int32

destX: the left coordinate for region to render

-> Int32

destY: the top coordinate for region to render

-> Int32

destWidth: the width of the region to render

-> Int32

destHeight: the height of the region to render

-> Double

offsetX: the offset in the X direction (currently rounded to an integer)

-> Double

offsetY: the offset in the Y direction (currently rounded to an integer)

-> Double

scaleX: the scale factor in the X direction

-> Double

scaleY: the scale factor in the Y direction

-> InterpType

interpType: the interpolation type for the transformation.

-> Int32

overallAlpha: overall alpha for source image (0..255)

-> Int32

checkX: the X offset for the checkboard (origin of checkboard is at -checkX, -checkY)

-> Int32

checkY: the Y offset for the checkboard

-> Int32

checkSize: the size of checks in the checkboard (must be a power of two)

-> Word32

color1: the color of check at upper left

-> Word32

color2: the color of the other check

-> m ()

Creates a transformation of the source image src by scaling by scaleX and scaleY then translating by offsetX and offsetY, then alpha blends the rectangle (destX ,destY, destWidth, destHeight) of the resulting image with a checkboard of the colors color1 and color2 and renders it onto the destination image.

If the source image has no alpha channel, and overallAlpha is 255, a fast path is used which omits the alpha blending and just performs the scaling.

See pixbufCompositeColorSimple for a simpler variant of this function suitable for many tasks.

compositeColorSimple

pixbufCompositeColorSimple

Arguments

:: (HasCallStack, MonadIO m, IsPixbuf a)

=> a

src: a Pixbuf

-> Int32

destWidth: the width of destination image

-> Int32

destHeight: the height of destination image

-> InterpType

interpType: the interpolation type for the transformation.

-> Int32

overallAlpha: overall alpha for source image (0..255)

-> Int32

checkSize: the size of checks in the checkboard (must be a power of two)

-> Word32

color1: the color of check at upper left

-> Word32

color2: the color of the other check

-> m (Maybe Pixbuf)

Returns: the new pixbuf

Creates a new pixbuf by scaling src to dest_width x dest_height and alpha blending the result with a checkboard of colors color1 and color2.

copy

pixbufCopy

Arguments

:: (HasCallStack, MonadIO m, IsPixbuf a)

=> a

pixbuf: A pixbuf.

-> m (Maybe Pixbuf)

Returns: A newly-created pixbuf

Creates a new GdkPixbuf with a copy of the information in the specified pixbuf.

Note that this does not copy the options set on the original GdkPixbuf, use pixbufCopyOptions for this.

copyArea

pixbufCopyArea

Arguments

:: (HasCallStack, MonadIO m, IsPixbuf a, IsPixbuf b)

=> a

srcPixbuf: Source pixbuf.

-> Int32

srcX: Source X coordinate within srcPixbuf.

-> Int32

srcY: Source Y coordinate within srcPixbuf.

-> Int32

width: Width of the area to copy.

-> Int32

height: Height of the area to copy.

-> b

destPixbuf: Destination pixbuf.

-> Int32

destX: X coordinate within destPixbuf.

-> Int32

destY: Y coordinate within destPixbuf.

-> m ()

Copies a rectangular area from src_pixbuf to dest_pixbuf.

Conversion of pixbuf formats is done automatically.

If the source rectangle overlaps the destination rectangle on the same pixbuf, it will be overwritten during the copy operation. Therefore, you can not use this function to scroll a pixbuf.

copyOptions

pixbufCopyOptions

Arguments

:: (HasCallStack, MonadIO m, IsPixbuf a, IsPixbuf b)

=> a

srcPixbuf: the source pixbuf

-> b

destPixbuf: the destination pixbuf

-> m Bool

Returns: TRUE on success.

Copies the key/value pair options attached to a GdkPixbuf to another GdkPixbuf.

This is useful to keep original metadata after having manipulated a file. However be careful to remove metadata which you've already applied, such as the "orientation" option after rotating the image.

Since: 2.36

fill

pixbufFill

Arguments

:: (HasCallStack, MonadIO m, IsPixbuf a)

=> a

pixbuf: a GdkPixbuf

-> Word32

pixel: RGBA pixel to used to clear (0xffffffff is opaque white, 0x00000000 transparent black)

-> m ()

Clears a pixbuf to the given RGBA value, converting the RGBA value into the pixbuf's pixel format.

The alpha component will be ignored if the pixbuf doesn't have an alpha channel.

flip

pixbufFlip

Arguments

:: (HasCallStack, MonadIO m, IsPixbuf a)

=> a

src: a Pixbuf

-> Bool

horizontal: TRUE to flip horizontally, FALSE to flip vertically

-> m (Maybe Pixbuf)

Returns: the new pixbuf

Flips a pixbuf horizontally or vertically and returns the result in a new pixbuf.

Since: 2.6

getBitsPerSample

pixbufGetBitsPerSample

Arguments

:: (HasCallStack, MonadIO m, IsPixbuf a)

=> a

pixbuf: A pixbuf.

-> m Int32

Returns: Number of bits per color sample.

Queries the number of bits per color sample in a pixbuf.

getByteLength

pixbufGetByteLength

Arguments

:: (HasCallStack, MonadIO m, IsPixbuf a)

=> a

pixbuf: A pixbuf

-> m Word64

Returns: The length of the pixel data.

Returns the length of the pixel data, in bytes.

Since: 2.26

getColorspace

pixbufGetColorspace

Arguments

:: (HasCallStack, MonadIO m, IsPixbuf a)

=> a

pixbuf: A pixbuf.

-> m Colorspace

Returns: Color space.

Queries the color space of a pixbuf.

getFileInfo

pixbufGetFileInfo

Arguments

:: (HasCallStack, MonadIO m)

=> [Char]

filename: The name of the file to identify.

-> m (Maybe PixbufFormat, Int32, Int32)

Returns: A GdkPixbufFormat describing the image format of the file

Parses an image file far enough to determine its format and size.

Since: 2.4

getFileInfoAsync

pixbufGetFileInfoAsync

Arguments

:: (HasCallStack, MonadIO m, IsCancellable a)

=> [Char]

filename: The name of the file to identify

-> Maybe a

cancellable: optional GCancellable object, NULL to ignore

-> Maybe AsyncReadyCallback

callback: a GAsyncReadyCallback to call when the file info is available

-> m ()

Asynchronously parses an image file far enough to determine its format and size.

For more details see pixbufGetFileInfo, which is the synchronous version of this function.

When the operation is finished, callback will be called in the main thread. You can then call pixbufGetFileInfoFinish to get the result of the operation.

Since: 2.32

getFileInfoFinish

pixbufGetFileInfoFinish

Arguments

:: (HasCallStack, MonadIO m, IsAsyncResult a)

=> a

asyncResult: a GAsyncResult

-> m (Maybe PixbufFormat, Int32, Int32)

Returns: A GdkPixbufFormat describing the image format of the file (Can throw GError)

Finishes an asynchronous pixbuf parsing operation started with pixbufGetFileInfoAsync.

Since: 2.32

getFormats

pixbufGetFormats

Arguments

:: (HasCallStack, MonadIO m)

=> m [PixbufFormat]

Returns: A list of support image formats.

Obtains the available information about the image formats supported by GdkPixbuf.

Since: 2.2

getHasAlpha

pixbufGetHasAlpha

Arguments

:: (HasCallStack, MonadIO m, IsPixbuf a)

=> a

pixbuf: A pixbuf.

-> m Bool

Returns: TRUE if it has an alpha channel, FALSE otherwise.

Queries whether a pixbuf has an alpha channel (opacity information).

getHeight

pixbufGetHeight

Arguments

:: (HasCallStack, MonadIO m, IsPixbuf a)

=> a

pixbuf: A pixbuf.

-> m Int32

Returns: Height in pixels.

Queries the height of a pixbuf.

getNChannels

pixbufGetNChannels

Arguments

:: (HasCallStack, MonadIO m, IsPixbuf a)

=> a

pixbuf: A pixbuf.

-> m Int32

Returns: Number of channels.

Queries the number of channels of a pixbuf.

getOption

pixbufGetOption

Arguments

:: (HasCallStack, MonadIO m, IsPixbuf a)

=> a

pixbuf: a GdkPixbuf

-> Text

key: a nul-terminated string.

-> m (Maybe Text)

Returns: the value associated with key

Looks up key in the list of options that may have been attached to the pixbuf when it was loaded, or that may have been attached by another function using pixbufSetOption.

For instance, the ANI loader provides "Title" and "Artist" options. The ICO, XBM, and XPM loaders provide "x_hot" and "y_hot" hot-spot options for cursor definitions. The PNG loader provides the tEXt ancillary chunk key/value pairs as options. Since 2.12, the TIFF and JPEG loaders return an "orientation" option string that corresponds to the embedded TIFF/Exif orientation tag (if present). Since 2.32, the TIFF loader sets the "multipage" option string to "yes" when a multi-page TIFF is loaded. Since 2.32 the JPEG and PNG loaders set "x-dpi" and "y-dpi" if the file contains image density information in dots per inch. Since 2.36.6, the JPEG loader sets the "comment" option with the comment EXIF tag.

getPixels

pixbufGetPixels

Arguments

:: (HasCallStack, MonadIO m, IsPixbuf a)

=> a

pixbuf: A pixbuf.

-> m ByteString

Returns: A pointer to the pixbuf's pixel data.

Queries a pointer to the pixel data of a pixbuf.

This function will cause an implicit copy of the pixbuf data if the pixbuf was created from read-only data.

Please see the section on image data for information about how the pixel data is stored in memory.

Since: 2.26

getRowstride

pixbufGetRowstride

Arguments

:: (HasCallStack, MonadIO m, IsPixbuf a)

=> a

pixbuf: A pixbuf.

-> m Int32

Returns: Distance between row starts.

Queries the rowstride of a pixbuf, which is the number of bytes between the start of a row and the start of the next row.

getWidth

pixbufGetWidth

Arguments

:: (HasCallStack, MonadIO m, IsPixbuf a)

=> a

pixbuf: A pixbuf.

-> m Int32

Returns: Width in pixels.

Queries the width of a pixbuf.

initModules

pixbufInitModules

Arguments

:: (HasCallStack, MonadIO m)

=> Text

path: Path to directory where the loaders.cache is installed

-> m ()

(Can throw GError)

Initalizes the gdk-pixbuf loader modules referenced by the loaders.cache file present inside that directory.

This is to be used by applications that want to ship certain loaders in a different location from the system ones.

This is needed when the OS or runtime ships a minimal number of loaders so as to reduce the potential attack surface of carefully crafted image files, especially for uncommon file types. Applications that require broader image file types coverage, such as image viewers, would be expected to ship the gdk-pixbuf modules in a separate location, bundled with the application in a separate directory from the OS or runtime- provided modules.

Since: 2.40

new

pixbufNew

Arguments

:: (HasCallStack, MonadIO m)

=> Colorspace

colorspace: Color space for image

-> Bool

hasAlpha: Whether the image should have transparency information

-> Int32

bitsPerSample: Number of bits per color sample

-> Int32

width: Width of image in pixels, must be > 0

-> Int32

height: Height of image in pixels, must be > 0

-> m (Maybe Pixbuf)

Returns: A newly-created pixel buffer

Creates a new GdkPixbuf structure and allocates a buffer for it.

If the allocation of the buffer failed, this function will return NULL.

The buffer has an optimal rowstride. Note that the buffer is not cleared; you will have to fill it completely yourself.

newFromBytes

pixbufNewFromBytes

Arguments

:: (HasCallStack, MonadIO m)

=> Bytes

data: Image data in 8-bit/sample packed format inside a Bytes

-> Colorspace

colorspace: Colorspace for the image data

-> Bool

hasAlpha: Whether the data has an opacity channel

-> Int32

bitsPerSample: Number of bits per sample

-> Int32

width: Width of the image in pixels, must be > 0

-> Int32

height: Height of the image in pixels, must be > 0

-> Int32

rowstride: Distance in bytes between row starts

-> m Pixbuf

Returns: A newly-created pixbuf

Creates a new Pixbuf out of in-memory readonly image data.

Currently only RGB images with 8 bits per sample are supported.

This is the GBytes variant of pixbufNewFromData, useful for language bindings.

Since: 2.32

newFromData

pixbufNewFromData

Arguments

:: (HasCallStack, MonadIO m)

=> Ptr Word8

data: Image data in 8-bit/sample packed format

-> Colorspace

colorspace: Colorspace for the image data

-> Bool

hasAlpha: Whether the data has an opacity channel

-> Int32

bitsPerSample: Number of bits per sample

-> Int32

width: Width of the image in pixels, must be > 0

-> Int32

height: Height of the image in pixels, must be > 0

-> Int32

rowstride: Distance in bytes between row starts

-> Maybe PixbufDestroyNotify

destroyFn: Function used to free the data when the pixbuf's reference count drops to zero, or Nothing if the data should not be freed

-> m Pixbuf

Returns: A newly-created pixbuf

Creates a new Pixbuf out of in-memory image data.

Currently only RGB images with 8 bits per sample are supported.

Since you are providing a pre-allocated pixel buffer, you must also specify a way to free that data. This is done with a function of type GdkPixbufDestroyNotify. When a pixbuf created with is finalized, your destroy notification function will be called, and it is its responsibility to free the pixel array.

See also: pixbufNewFromBytes

newFromFile

pixbufNewFromFile

Arguments

:: (HasCallStack, MonadIO m)

=> [Char]

filename: Name of file to load, in the GLib file name encoding

-> m (Maybe Pixbuf)

Returns: A newly-created pixbuf (Can throw GError)

Creates a new pixbuf by loading an image from a file.

The file format is detected automatically.

If NULL is returned, then error will be set. Possible errors are:

• the file could not be opened
• there is no loader for the file's format
• there is not enough memory to allocate the image buffer
• the image buffer contains invalid data

The error domains are GDK_PIXBUF_ERROR and G_FILE_ERROR.

newFromFileAtScale

pixbufNewFromFileAtScale

Arguments

:: (HasCallStack, MonadIO m)

=> [Char]

filename: Name of file to load, in the GLib file name encoding

-> Int32

width: The width the image should have or -1 to not constrain the width

-> Int32

height: The height the image should have or -1 to not constrain the height

-> Bool

preserveAspectRatio: TRUE to preserve the image's aspect ratio

-> m (Maybe Pixbuf)

Returns: A newly-created pixbuf (Can throw GError)

Creates a new pixbuf by loading an image from a file.

The file format is detected automatically.

If NULL is returned, then error will be set. Possible errors are:

• the file could not be opened
• there is no loader for the file's format
• there is not enough memory to allocate the image buffer
• the image buffer contains invalid data

The error domains are GDK_PIXBUF_ERROR and G_FILE_ERROR.

The image will be scaled to fit in the requested size, optionally preserving the image's aspect ratio.

When preserving the aspect ratio, a width of -1 will cause the image to be scaled to the exact given height, and a height of -1 will cause the image to be scaled to the exact given width. When not preserving aspect ratio, a width or height of -1 means to not scale the image at all in that dimension. Negative values for width and height are allowed since 2.8.

Since: 2.6

newFromFileAtSize

pixbufNewFromFileAtSize

Arguments

:: (HasCallStack, MonadIO m)

=> [Char]

filename: Name of file to load, in the GLib file name encoding

-> Int32

width: The width the image should have or -1 to not constrain the width

-> Int32

height: The height the image should have or -1 to not constrain the height

-> m (Maybe Pixbuf)

Returns: A newly-created pixbuf (Can throw GError)

Creates a new pixbuf by loading an image from a file.

The file format is detected automatically.

If NULL is returned, then error will be set. Possible errors are:

• the file could not be opened
• there is no loader for the file's format
• there is not enough memory to allocate the image buffer
• the image buffer contains invalid data

The error domains are GDK_PIXBUF_ERROR and G_FILE_ERROR.

The image will be scaled to fit in the requested size, preserving the image's aspect ratio. Note that the returned pixbuf may be smaller than width x height, if the aspect ratio requires it. To load and image at the requested size, regardless of aspect ratio, use pixbufNewFromFileAtScale.

Since: 2.4

newFromInline

pixbufNewFromInline

Arguments

:: (HasCallStack, MonadIO m)

=> ByteString

data: Byte data containing a serialized GdkPixdata structure

-> Bool

copyPixels: Whether to copy the pixel data, or use direct pointers data for the resulting pixbuf

-> m Pixbuf

Returns: A newly-created pixbuf (Can throw GError)

Deprecated: (Since version 2.32)Use GResource instead.

Creates a GdkPixbuf from a flat representation that is suitable for storing as inline data in a program.

This is useful if you want to ship a program with images, but don't want to depend on any external files.

GdkPixbuf ships with a program called gdk-pixbuf-csource, which allows for conversion of GdkPixbufs into such a inline representation.

In almost all cases, you should pass the --raw option to gdk-pixbuf-csource. A sample invocation would be:

gdk-pixbuf-csource --raw --name=myimage_inline myimage.png

For the typical case where the inline pixbuf is read-only static data, you don't need to copy the pixel data unless you intend to write to it, so you can pass FALSE for copy_pixels. If you pass --rle to gdk-pixbuf-csource, a copy will be made even if copy_pixels is FALSE, so using this option is generally a bad idea.

If you create a pixbuf from const inline data compiled into your program, it's probably safe to ignore errors and disable length checks, since things will always succeed:

c code

pixbuf = gdk_pixbuf_new_from_inline (-1, myimage_inline, FALSE, NULL);

For non-const inline data, you could get out of memory. For untrusted inline data located at runtime, you could have corrupt inline data in addition.

newFromResource

pixbufNewFromResource

Arguments

:: (HasCallStack, MonadIO m)

=> Text

resourcePath: the path of the resource file

-> m (Maybe Pixbuf)

Returns: A newly-created pixbuf (Can throw GError)

Creates a new pixbuf by loading an image from an resource.

The file format is detected automatically. If NULL is returned, then error will be set.

Since: 2.26

newFromResourceAtScale

pixbufNewFromResourceAtScale

Arguments

:: (HasCallStack, MonadIO m)

=> Text

resourcePath: the path of the resource file

-> Int32

width: The width the image should have or -1 to not constrain the width

-> Int32

height: The height the image should have or -1 to not constrain the height

-> Bool

preserveAspectRatio: TRUE to preserve the image's aspect ratio

-> m (Maybe Pixbuf)

Returns: A newly-created pixbuf (Can throw GError)

Creates a new pixbuf by loading an image from an resource.

The file format is detected automatically. If NULL is returned, then error will be set.

The image will be scaled to fit in the requested size, optionally preserving the image's aspect ratio. When preserving the aspect ratio, a width of -1 will cause the image to be scaled to the exact given height, and a height of -1 will cause the image to be scaled to the exact given width. When not preserving aspect ratio, a width or height of -1 means to not scale the image at all in that dimension.

The stream is not closed.

Since: 2.26

newFromStream

pixbufNewFromStream

Arguments

:: (HasCallStack, MonadIO m, IsInputStream a, IsCancellable b)

=> a

stream: a GInputStream to load the pixbuf from

-> Maybe b

cancellable: optional GCancellable object, NULL to ignore

-> m (Maybe Pixbuf)

Returns: A newly-created pixbuf (Can throw GError)

Creates a new pixbuf by loading an image from an input stream.

The file format is detected automatically.

If NULL is returned, then error will be set.

The cancellable can be used to abort the operation from another thread. If the operation was cancelled, the error G_IO_ERROR_CANCELLED will be returned. Other possible errors are in the GDK_PIXBUF_ERROR and G_IO_ERROR domains.

The stream is not closed.

Since: 2.14

newFromStreamAsync

pixbufNewFromStreamAsync

Arguments

:: (HasCallStack, MonadIO m, IsInputStream a, IsCancellable b)

=> a

stream: a GInputStream from which to load the pixbuf

-> Maybe b

cancellable: optional GCancellable object, NULL to ignore

-> Maybe AsyncReadyCallback

callback: a GAsyncReadyCallback to call when the pixbuf is loaded

-> m ()

Creates a new pixbuf by asynchronously loading an image from an input stream.

For more details see pixbufNewFromStream, which is the synchronous version of this function.

When the operation is finished, callback will be called in the main thread. You can then call pixbufNewFromStreamFinish to get the result of the operation.

Since: 2.24

newFromStreamAtScale

pixbufNewFromStreamAtScale

Arguments

:: (HasCallStack, MonadIO m, IsInputStream a, IsCancellable b)

=> a

stream: a GInputStream to load the pixbuf from

-> Int32

width: The width the image should have or -1 to not constrain the width

-> Int32

height: The height the image should have or -1 to not constrain the height

-> Bool

preserveAspectRatio: TRUE to preserve the image's aspect ratio

-> Maybe b

cancellable: optional GCancellable object, NULL to ignore

-> m (Maybe Pixbuf)

Returns: A newly-created pixbuf (Can throw GError)

Creates a new pixbuf by loading an image from an input stream.

The file format is detected automatically. If NULL is returned, then error will be set. The cancellable can be used to abort the operation from another thread. If the operation was cancelled, the error G_IO_ERROR_CANCELLED will be returned. Other possible errors are in the GDK_PIXBUF_ERROR and G_IO_ERROR domains.

The image will be scaled to fit in the requested size, optionally preserving the image's aspect ratio.

When preserving the aspect ratio, a width of -1 will cause the image to be scaled to the exact given height, and a height of -1 will cause the image to be scaled to the exact given width. If both width and height are given, this function will behave as if the smaller of the two values is passed as -1.

When not preserving aspect ratio, a width or height of -1 means to not scale the image at all in that dimension.

The stream is not closed.

Since: 2.14

newFromStreamAtScaleAsync

pixbufNewFromStreamAtScaleAsync

Arguments

:: (HasCallStack, MonadIO m, IsInputStream a, IsCancellable b)

=> a

stream: a GInputStream from which to load the pixbuf

-> Int32

width: the width the image should have or -1 to not constrain the width

-> Int32

height: the height the image should have or -1 to not constrain the height

-> Bool

preserveAspectRatio: TRUE to preserve the image's aspect ratio

-> Maybe b

cancellable: optional GCancellable object, NULL to ignore

-> Maybe AsyncReadyCallback

callback: a GAsyncReadyCallback to call when the pixbuf is loaded

-> m ()

Creates a new pixbuf by asynchronously loading an image from an input stream.

For more details see pixbufNewFromStreamAtScale, which is the synchronous version of this function.

When the operation is finished, callback will be called in the main thread. You can then call pixbufNewFromStreamFinish to get the result of the operation.

Since: 2.24

newFromStreamFinish

pixbufNewFromStreamFinish

Arguments

:: (HasCallStack, MonadIO m, IsAsyncResult a)

=> a

asyncResult: a GAsyncResult

-> m (Maybe Pixbuf)

Returns: the newly created pixbuf (Can throw GError)

Finishes an asynchronous pixbuf creation operation started with pixbufNewFromStreamAsync.

Since: 2.24

newFromXpmData

pixbufNewFromXpmData

Arguments

:: (HasCallStack, MonadIO m)

=> [Text]

data: Pointer to inline XPM data.

-> m Pixbuf

Returns: A newly-created pixbuf

Creates a new pixbuf by parsing XPM data in memory.

This data is commonly the result of including an XPM file into a program's C source.

newSubpixbuf

pixbufNewSubpixbuf

Arguments

:: (HasCallStack, MonadIO m, IsPixbuf a)

=> a

srcPixbuf: a GdkPixbuf

-> Int32

srcX: X coord in srcPixbuf

-> Int32

srcY: Y coord in srcPixbuf

-> Int32

width: width of region in srcPixbuf

-> Int32

height: height of region in srcPixbuf

-> m Pixbuf

Returns: a new pixbuf

Creates a new pixbuf which represents a sub-region of src_pixbuf.

The new pixbuf shares its pixels with the original pixbuf, so writing to one affects both. The new pixbuf holds a reference to src_pixbuf, so src_pixbuf will not be finalized until the new pixbuf is finalized.

Note that if src_pixbuf is read-only, this function will force it to be mutable.

readPixelBytes

pixbufReadPixelBytes

Arguments

:: (HasCallStack, MonadIO m, IsPixbuf a)

=> a

pixbuf: A pixbuf

-> m Bytes

Returns: A new reference to a read-only copy of the pixel data. Note that for mutable pixbufs, this function will incur a one-time copy of the pixel data for conversion into the returned Bytes.

Provides a Bytes buffer containing the raw pixel data; the data must not be modified.

This function allows skipping the implicit copy that must be made if gdk_pixbuf_get_pixels() is called on a read-only pixbuf.

Since: 2.32

readPixels

pixbufReadPixels

Arguments

:: (HasCallStack, MonadIO m, IsPixbuf a)

=> a

pixbuf: A pixbuf

-> m Word8

Returns: a read-only pointer to the raw pixel data

Provides a read-only pointer to the raw pixel data.

This function allows skipping the implicit copy that must be made if gdk_pixbuf_get_pixels() is called on a read-only pixbuf.

Since: 2.32

removeOption

pixbufRemoveOption

Arguments

:: (HasCallStack, MonadIO m, IsPixbuf a)

=> a

pixbuf: a GdkPixbuf

-> Text

key: a nul-terminated string representing the key to remove.

-> m Bool

Returns: TRUE if an option was removed, FALSE if not.

Removes the key/value pair option attached to a GdkPixbuf.

Since: 2.36

rotateSimple

pixbufRotateSimple

Arguments

:: (HasCallStack, MonadIO m, IsPixbuf a)

=> a

src: a Pixbuf

-> PixbufRotation

angle: the angle to rotate by

-> m (Maybe Pixbuf)

Returns: the new pixbuf

Rotates a pixbuf by a multiple of 90 degrees, and returns the result in a new pixbuf.

If angle is 0, this function will return a copy of src.

Since: 2.6

saturateAndPixelate

pixbufSaturateAndPixelate

Arguments

:: (HasCallStack, MonadIO m, IsPixbuf a, IsPixbuf b)

=> a

src: source image

-> b

dest: place to write modified version of src

-> Float

saturation: saturation factor

-> Bool

pixelate: whether to pixelate

-> m ()

Modifies saturation and optionally pixelates src, placing the result in dest.

The src and dest pixbufs must have the same image format, size, and rowstride.

The src and dest arguments may be the same pixbuf with no ill effects.

If saturation is 1.0 then saturation is not changed. If it's less than 1.0, saturation is reduced (the image turns toward grayscale); if greater than 1.0, saturation is increased (the image gets more vivid colors).

If pixelate is TRUE, then pixels are faded in a checkerboard pattern to create a pixelated image.

saveToBufferv

pixbufSaveToBufferv

Arguments

:: (HasCallStack, MonadIO m, IsPixbuf a)

=> a

pixbuf: a GdkPixbuf.

-> Text

type: name of file format.

-> Maybe [Text]

optionKeys: name of options to set

-> Maybe [Text]

optionValues: values for named options

-> m ByteString

(Can throw GError)

Vector version of gdk_pixbuf_save_to_buffer().

Saves pixbuf to a new buffer in format type, which is currently "jpeg", "tiff", "png", "ico" or "bmp".

See Pixbuf.save_to_buffer() for more details.

Since: 2.4

saveToCallbackv

pixbufSaveToCallbackv

Arguments

:: (HasCallStack, MonadIO m, IsPixbuf a)

=> a

pixbuf: a GdkPixbuf.

-> PixbufSaveFunc

saveFunc: a function that is called to save each block of data that the save routine generates.

-> Text

type: name of file format.

-> Maybe [Text]

optionKeys: name of options to set

-> Maybe [Text]

optionValues: values for named options

-> m ()

(Can throw GError)

Vector version of gdk_pixbuf_save_to_callback().

Saves pixbuf to a callback in format type, which is currently "jpeg", "png", "tiff", "ico" or "bmp".

If error is set, FALSE will be returned.

See Pixbuf.save_to_callback() for more details.

Since: 2.4

saveToStreamFinish

pixbufSaveToStreamFinish

Arguments

:: (HasCallStack, MonadIO m, IsAsyncResult a)

=> a

asyncResult: a GAsyncResult

-> m ()

(Can throw GError)

Finishes an asynchronous pixbuf save operation started with gdk_pixbuf_save_to_stream_async().

Since: 2.24

saveToStreamv

pixbufSaveToStreamv

Arguments

:: (HasCallStack, MonadIO m, IsPixbuf a, IsOutputStream b, IsCancellable c)

=> a

pixbuf: a GdkPixbuf

-> b

stream: a GOutputStream to save the pixbuf to

-> Text

type: name of file format

-> Maybe [Text]

optionKeys: name of options to set

-> Maybe [Text]

optionValues: values for named options

-> Maybe c

cancellable: optional GCancellable object, NULL to ignore

-> m ()

(Can throw GError)

Saves pixbuf to an output stream.

Supported file formats are currently "jpeg", "tiff", "png", "ico" or "bmp".

See Pixbuf.save_to_stream() for more details.

Since: 2.36

saveToStreamvAsync

pixbufSaveToStreamvAsync

Arguments

:: (HasCallStack, MonadIO m, IsPixbuf a, IsOutputStream b, IsCancellable c)

=> a

pixbuf: a GdkPixbuf

-> b

stream: a GOutputStream to which to save the pixbuf

-> Text

type: name of file format

-> Maybe [Text]

optionKeys: name of options to set

-> Maybe [Text]

optionValues: values for named options

-> Maybe c

cancellable: optional GCancellable object, NULL to ignore

-> Maybe AsyncReadyCallback

callback: a GAsyncReadyCallback to call when the pixbuf is saved

-> m ()

Saves pixbuf to an output stream asynchronously.

For more details see pixbufSaveToStreamv, which is the synchronous version of this function.

When the operation is finished, callback will be called in the main thread.

You can then call pixbufSaveToStreamFinish to get the result of the operation.

Since: 2.36

savev

pixbufSavev

Arguments

:: (HasCallStack, MonadIO m, IsPixbuf a)

=> a

pixbuf: a GdkPixbuf.

-> [Char]

filename: name of file to save.

-> Text

type: name of file format.

-> Maybe [Text]

optionKeys: name of options to set

-> Maybe [Text]

optionValues: values for named options

-> m ()

(Can throw GError)

Vector version of gdk_pixbuf_save().

Saves pixbuf to a file in type, which is currently "jpeg", "png", "tiff", "ico" or "bmp".

If error is set, FALSE will be returned.

See Pixbuf.save() for more details.

scale

pixbufScale

Arguments

:: (HasCallStack, MonadIO m, IsPixbuf a, IsPixbuf b)

=> a

src: a Pixbuf

-> b

dest: the Pixbuf into which to render the results

-> Int32

destX: the left coordinate for region to render

-> Int32

destY: the top coordinate for region to render

-> Int32

destWidth: the width of the region to render

-> Int32

destHeight: the height of the region to render

-> Double

offsetX: the offset in the X direction (currently rounded to an integer)

-> Double

offsetY: the offset in the Y direction (currently rounded to an integer)

-> Double

scaleX: the scale factor in the X direction

-> Double

scaleY: the scale factor in the Y direction

-> InterpType

interpType: the interpolation type for the transformation.

-> m ()

Creates a transformation of the source image src by scaling by scaleX and scaleY then translating by offsetX and offsetY, then renders the rectangle (destX, destY, destWidth, destHeight) of the resulting image onto the destination image replacing the previous contents.

Try to use pixbufScaleSimple first; this function is the industrial-strength power tool you can fall back to, if pixbufScaleSimple isn't powerful enough.

If the source rectangle overlaps the destination rectangle on the same pixbuf, it will be overwritten during the scaling which results in rendering artifacts.

scaleSimple

pixbufScaleSimple

Arguments

:: (HasCallStack, MonadIO m, IsPixbuf a)

=> a

src: a Pixbuf

-> Int32

destWidth: the width of destination image

-> Int32

destHeight: the height of destination image

-> InterpType

interpType: the interpolation type for the transformation.

-> m (Maybe Pixbuf)

Returns: the new pixbuf

Create a new pixbuf containing a copy of src scaled to dest_width x dest_height.

This function leaves src unaffected.

The interp_type should be GDK_INTERP_NEAREST if you want maximum speed (but when scaling down GDK_INTERP_NEAREST is usually unusably ugly). The default interp_type should be GDK_INTERP_BILINEAR which offers reasonable quality and speed.

You can scale a sub-portion of src by creating a sub-pixbuf pointing into src; see pixbufNewSubpixbuf.

If dest_width and dest_height are equal to the width and height of src, this function will return an unscaled copy of src.

For more complicated scaling/alpha blending see pixbufScale and pixbufComposite.

setOption

pixbufSetOption

Arguments

:: (HasCallStack, MonadIO m, IsPixbuf a)

=> a

pixbuf: a GdkPixbuf

-> Text

key: a nul-terminated string.

-> Text

value: a nul-terminated string.

-> m Bool

Returns: TRUE on success

Attaches a key/value pair as an option to a GdkPixbuf.

If key already exists in the list of options attached to the pixbuf, the new value is ignored and FALSE is returned.

Since: 2.2

Properties

bitsPerSample

The number of bits per sample.

Currently only 8 bit per sample are supported.

constructPixbufBitsPerSample :: (IsPixbuf o, MonadIO m) => Int32 -> m (GValueConstruct o)

Construct a GValueConstruct with valid value for the “bits-per-sample” property. This is rarely needed directly, but it is used by new.

getPixbufBitsPerSample :: (MonadIO m, IsPixbuf o) => o -> m Int32

Get the value of the “bits-per-sample” property. When overloading is enabled, this is equivalent to

get pixbuf #bitsPerSample

colorspace

The color space of the pixbuf.

Currently, only GDK_COLORSPACE_RGB is supported.

constructPixbufColorspace :: (IsPixbuf o, MonadIO m) => Colorspace -> m (GValueConstruct o)

Construct a GValueConstruct with valid value for the “colorspace” property. This is rarely needed directly, but it is used by new.

getPixbufColorspace :: (MonadIO m, IsPixbuf o) => o -> m Colorspace

Get the value of the “colorspace” property. When overloading is enabled, this is equivalent to

get pixbuf #colorspace

hasAlpha

Whether the pixbuf has an alpha channel.

constructPixbufHasAlpha :: (IsPixbuf o, MonadIO m) => Bool -> m (GValueConstruct o)

Construct a GValueConstruct with valid value for the “has-alpha” property. This is rarely needed directly, but it is used by new.

getPixbufHasAlpha :: (MonadIO m, IsPixbuf o) => o -> m Bool

Get the value of the “has-alpha” property. When overloading is enabled, this is equivalent to

get pixbuf #hasAlpha

height

The number of rows of the pixbuf.

constructPixbufHeight :: (IsPixbuf o, MonadIO m) => Int32 -> m (GValueConstruct o)

Construct a GValueConstruct with valid value for the “height” property. This is rarely needed directly, but it is used by new.

getPixbufHeight :: (MonadIO m, IsPixbuf o) => o -> m Int32

Get the value of the “height” property. When overloading is enabled, this is equivalent to

get pixbuf #height

nChannels

The number of samples per pixel.

Currently, only 3 or 4 samples per pixel are supported.

constructPixbufNChannels :: (IsPixbuf o, MonadIO m) => Int32 -> m (GValueConstruct o)

Construct a GValueConstruct with valid value for the “n-channels” property. This is rarely needed directly, but it is used by new.

getPixbufNChannels :: (MonadIO m, IsPixbuf o) => o -> m Int32

Get the value of the “n-channels” property. When overloading is enabled, this is equivalent to

get pixbuf #nChannels

pixelBytes

No description available in the introspection data.

constructPixbufPixelBytes :: (IsPixbuf o, MonadIO m) => Bytes -> m (GValueConstruct o)

Construct a GValueConstruct with valid value for the “pixel-bytes” property. This is rarely needed directly, but it is used by new.

getPixbufPixelBytes :: (MonadIO m, IsPixbuf o) => o -> m (Maybe Bytes)

Get the value of the “pixel-bytes” property. When overloading is enabled, this is equivalent to

get pixbuf #pixelBytes

pixels

A pointer to the pixel data of the pixbuf.

constructPixbufPixels :: (IsPixbuf o, MonadIO m) => Ptr () -> m (GValueConstruct o)

Construct a GValueConstruct with valid value for the “pixels” property. This is rarely needed directly, but it is used by new.

getPixbufPixels :: (MonadIO m, IsPixbuf o) => o -> m (Ptr ())

Get the value of the “pixels” property. When overloading is enabled, this is equivalent to

get pixbuf #pixels

rowstride

The number of bytes between the start of a row and the start of the next row.

This number must (obviously) be at least as large as the width of the pixbuf.

constructPixbufRowstride :: (IsPixbuf o, MonadIO m) => Int32 -> m (GValueConstruct o)

Construct a GValueConstruct with valid value for the “rowstride” property. This is rarely needed directly, but it is used by new.

getPixbufRowstride :: (MonadIO m, IsPixbuf o) => o -> m Int32

Get the value of the “rowstride” property. When overloading is enabled, this is equivalent to

get pixbuf #rowstride

width

The number of columns of the pixbuf.

constructPixbufWidth :: (IsPixbuf o, MonadIO m) => Int32 -> m (GValueConstruct o)

Construct a GValueConstruct with valid value for the “width” property. This is rarely needed directly, but it is used by new.

getPixbufWidth :: (MonadIO m, IsPixbuf o) => o -> m Int32

Get the value of the “width” property. When overloading is enabled, this is equivalent to

get pixbuf #width