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L_InitBitmap

Summary

Initializes the fields in a bitmap handle.

Syntax

#include "l_bitmap.h"

L_LTKRN_API L_INT L_InitBitmap(pBitmap, uStructSize, nWidth, nHeight, nBitsPerPixel)

Parameters

pBITMAPHANDLE pBitmap

Pointer to the bitmap handle to initialize.

L_UINT uStructSize

Size in bytes, of the structure pointed to by pBitmap, for versioning. Use sizeof(BITMAPHANDLE).

L_INT nWidth

Width of the image in pixels.

L_INT nHeight

Height of the image in pixels.

L_INT nBitsPerPixel

Number of bits per pixel in the image. Valid values are:

Value	Meaning
1	For a 1-bit image.
2	For a 2-bit image.
3	For a 3-bit image.
4	For a 4-bit image.
5	For a 5-bit image.
6	For a 6-bit image.
7	For a 7-bit image.
8	For an 8-bit image.
12	For a 12-bit image.
16	For a 16-bit image.
24	For a 24-bit image.
32	For a 32-bit image.
48	For a 48-bit image.
64	For a 64-bit image.

Returns

Value	Meaning
SUCCESS	The function was successful.
< 1	An error occurred. Refer to Return Codes.

Comments

Support for 12 and 16-bit grayscale images is only available in the Document and Medical Imaging toolkits.

This is a low-level function that is necessary only if you need to initialize the bitmap handle and allocate memory in separate steps when creating a bitmap from scratch. L_CreateBitmap is usually a better choice.

This function must be called before using L_AllocateBitmap. This function only initializes the fields in the bitmap handle; it does not allocate any memory. If all zeroes are passed as the nWidth, nHeight, and nBitsPerPixel into this function, then all fields in the bitmap handle will be set to 0. Otherwise, all fields will be set to zero except the fields listed below.

When this function is called, the following fields will be set:

Field	Value
Order	ORDER_RGB if you specify 8 bits per pixel or less; ORDER_GRAY for 12 or 16-bit grayscale; ORDER_BGR otherwise. ORDER_GRAY is valid only for 12 and 16-bit grayscale images and is only available in the Document and Medical Imaging toolkits. Please note that a 16-bpp image may be color or grayscale. If you are working with a 16-bit grayscale image, explicitly set BITMAPHANDLE.Order to ORDER_GRAY. By default, the order for a 16-bit image will be set to ORDER_BGR.
DitherMethod	Set by the L_DefaultDithering function
ViewPerspective	BOTTOM_LEFT [2]
Width	As passed into the function
Height	As passed into the function
BytesPerLine	Calculated using the specified width and bits per pixel, rounded on a 4-byte boundary
XResolution	150
YResolution	150