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XCreateImage(3)			XLIB FUNCTIONS		       XCreateImage(3)

NAME
       XInitImage,  XCreateImage,  XGetPixel, XPutPixel, XSubImage, XAddPixel,
       XDestroyImage - image utilities

SYNTAX
       Status XInitImage(XImage	*image);

       XImage *XCreateImage(Display *display,  Visual  *visual,	 unsigned  int
	      depth,  int  format, int offset, char *data, unsigned int	width,
	      unsigned int height, int bitmap_pad, int bytes_per_line);

       unsigned	long XGetPixel(XImage *ximage, int x, int y);

       int XPutPixel(XImage *ximage, int x, int	y, unsigned long pixel);

       XImage *XSubImage(XImage	*ximage, int x,	int  y,	 unsigned  int	subim-
	      age_width, unsigned int subimage_height);

       int XAddPixel(XImage *ximage, long value);

       int XDestroyImage(XImage	*ximage);

ARGUMENTS
       bitmap_pad
		 Specifies the quantum of a scanline (8, 16, or	32).  In other
		 words,	the start of one scanline is separated in client  mem-
		 ory  from the start of	the next scanline by an	integer	multi-
		 ple of	this many bits.

       bytes_per_line
		 Specifies the number of bytes in the client image between the
		 start of one scanline and the start of	the next.

       data	 Specifies the image data.

       depth	 Specifies the depth of	the image.

       display	 Specifies the connection to the X server.

       format	 Specifies  the	 format	for the	image.	You can	pass XYBitmap,
		 XYPixmap, or ZPixmap.

       height	 Specifies the height of the image, in pixels.

       offset	 Specifies the number of pixels	to ignore at the beginning  of
		 the scanline.

       pixel	 Specifies the new pixel value.

       subimage_height
		 Specifies the height of the new subimage, in pixels.

       subimage_width
		 Specifies the width of	the new	subimage, in pixels.

       value	 Specifies the constant	value that is to be added.

       visual	 Specifies the Visual structure.

       width	 Specifies the width of	the image, in pixels.

       ximage	 Specifies the image.

       x
       y	 Specify the x and y coordinates.

DESCRIPTION
       The  XInitImage	function  initializes  the internal image manipulation
       routines	of an image structure, based on	 the  values  of  the  various
       structure  members.   All  fields  other	than the manipulation routines
       must already be initialized.  If	the  bytes_per_line  member  is	 zero,
       XInitImage  will	 assume	the image data is contiguous in	memory and set
       the bytes_per_line member to an appropriate value based	on  the	 other
       members;	otherwise, the value of	bytes_per_line is not changed.	All of
       the manipulation	routines are initialized to functions that other  Xlib
       image manipulation functions need to operate on the type	of image spec-
       ified by	the rest of the	structure.

       This function must be called for	any image constructed  by  the	client
       before passing it to any	other Xlib function.  Image structures created
       or returned by Xlib do not need to be initialized in this fashion.

       This function returns a nonzero status if initialization	of the	struc-
       ture  is	 successful.  It returns zero if it detected some error	or in-
       consistency in the structure, in	which case the image is	not changed.

       The XCreateImage	function allocates the memory  needed  for  an	XImage
       structure for the specified display but does not	allocate space for the
       image itself.  Rather, it initializes the structure byte-order, bit-or-
       der,  and  bitmap-unit values from the display and returns a pointer to
       the XImage structure.  The red, green, and blue mask values are defined
       for  Z  format  images  only  and are derived from the Visual structure
       passed in.  Other values	also are passed	in.  The  offset  permits  the
       rapid  displaying  of  the  image without requiring each	scanline to be
       shifted into position.  If you pass a  zero  value  in  bytes_per_line,
       Xlib assumes that the scanlines are contiguous in memory	and calculates
       the value of bytes_per_line itself.

       Note that when the image	is created using XCreateImage,	XGetImage,  or
       XSubImage,  the destroy procedure that the XDestroyImage	function calls
       frees both the image structure and the data pointed  to	by  the	 image
       structure.

       The  basic  functions used to get a pixel, set a	pixel, create a	subim-
       age, and	add a constant value to	an image are defined in	the image  ob-
       ject.   The  functions  in this section are really macro	invocations of
       the functions in	the image object and are defined in

       The XGetPixel function returns the specified pixel from the  named  im-
       age.   The  pixel  value	is returned in normalized format (that is, the
       least significant byte of the long is the least significant byte	of the
       pixel).	The image must contain the x and y coordinates.

       The XPutPixel function overwrites the pixel in the named	image with the
       specified pixel value.  The input pixel value  must  be	in  normalized
       format  (that  is,  the least significant byte of the long is the least
       significant byte	of the pixel).	The image must contain the x and y co-
       ordinates.

       The  XSubImage  function	creates	a new image that is a subsection of an
       existing	one.  It allocates the memory necessary	 for  the  new	XImage
       structure  and  returns a pointer to the	new image.  The	data is	copied
       from the	source image, and the image must contain the rectangle defined
       by x, y,	subimage_width,	and subimage_height.

       The  XAddPixel  function	adds a constant	value to every pixel in	an im-
       age.  It	is useful when you have	a base	pixel  value  from  allocating
       color resources and need	to manipulate the image	to that	form.

       The  XDestroyImage  function deallocates	the memory associated with the
       XImage structure.

SEE ALSO
       XPutImage(3)
       Xlib - C	Language X Interface

X Version 11			 libX11	1.6.12		       XCreateImage(3)

NAME | SYNTAX | ARGUMENTS | DESCRIPTION | SEE ALSO

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