imgbmpprocess.h

用纯C写的读RGB文件格式的代码

/*
  *	Filename:		ImgReadBMP.h
  *
  *	Read bmp file using standard C.
  *
  *	Author:		gomo
  *	Date:		2007-05-16
  */

#ifndef __ImgReadBMP_H
#define __ImgReadBMP_H

#include "dh_def.h"


#define DIB_HEADER_MARKER   ((short int) ('M' << 8) | 'B')

struct _BmpFileHeader
{
	short int	bfType;		//Specifies the file type. It must be BM
	int 		bfSize;		//Specifies the size, in bytes, of the bitmap file
	short int	bfReserved1;	//Reserved; must be zero
	short int 	bfReserved2;	//Reserved; must be zero
	int 		bfOffBits;		//Specifies the offset, in bytes, from the BITMAPFILEHEADER structure to the bitmap bits
}__attribute__((packed,aligned(2)));
typedef struct _BmpFileHeader BmpFileHeader;

struct _BmpInfoHeader
{
	long int biSize;		//Specifies the number of bytes required by the structure.
	long int biWidth;		//biWidth Specifies the width of the bitmap.
	long int biHeight;		//Specifies the height of the bitmap, in pixels.
	short int biPlanes;		//Specifies the number of planes for the target device. This value must be set to 1. 
	short int biBitCount ;	//Specifies the number of bits per pixel,such as 1,4,8,24 .
	long int biCompression;//Specifies the type of compression for a compressed bottom-up bitmap 
						//(top-down DIBs cannot be compressed). This member can be one of the 
						//following values: BI_RGB,BI_RLE8,BI_RLE4,BI_BITFIELDS,BI_JPEG.
						
	long int biSizeImage;	//Specifies the size, in bytes, of the image. This may be set to zero for BI_RGB bitmaps.
	
	long int biXPelsPerMeter;//Specifies the horizontal resolution, in pixels per meter, of the target device for the 
						//bitmap. An application can use this value to select a bitmap from a resource 
						//group that best matches the characteristics of the current device.
						
	long int biYPelsPerMeter;//Specifies the vertical resolution, in pixels per meter, of the target device for the bitmap.
	
	long int biClrUsed;		//Specifies the number of color indexes in the color table that are actually used by the bitmap.
						//If this value is zero, the bitmap uses the maximum number of colors corresponding 
						//to the value of the biBitCount member for the compression mode specified by biCompression.
						
	long int biClrImportant;	//Specifies the number of color indexes that are required for displaying the bitmap. If this value is zero,
						//all colors are required.
}__attribute__((packed,aligned(2)));
typedef struct _BmpInfoHeader BmpInfoHeader;


struct _RGBQuad
{
	unsigned char rgbBlue;		//Specifies the intensity of blue in the color. 
	unsigned char rgbGreen;	//Specifies the intensity of green in the color. 
 	unsigned char rgbRed;		//Specifies the intensity of red in the color. 
 	unsigned char rgbReserved;	//Reserved; must be zero.
}__attribute__((packed,aligned(2)));
typedef struct _RGBQuad RGBQuad;

/*
  *	This function DhReadBMPImg read bmp file information.
  *
  *	Parameters:
  *	char *FileName:		Input bmp file name;
  *	BmpFileHeader *BmpFH:Save bmp file herder;
  *	BmpInfoHeader *BmpIH:Save bmp file Information herder;
  *
  *
  *	Return value:
  *	0:	Success;
  *	-1:	File cannot open;
  *	-2:	Alloc memory failed;
  *	-3:	Read bmp file header failed;
  *	-4:	The format of file is not bmp;
  *	-5:	Read bmp file information header failed;
  *	-6:	Bits count invalid.
  *	-7:	Bmp file offset is wrong.
  */
int
DhReadBMPImgInfo(
						IN char *pFileName, 
						OUT BmpFileHeader *pBmpFH,
						OUT BmpInfoHeader *pBmpIH
						);

/*
  *	RGB2BGR
  *
  *	Convert 24bits RGB data to 24bits BGR data
  */
int 
RGB2BGR(
			INOUT unsigned char *pBbuf, 
			IN int iWidthPix, 
			IN int iHeightPix
			);


/*
  *	BGR2RGB
  *
  *	Convert 24bits BGR data to 24bits RGB data
  */
int 
BGR2RGB(
			INOUT unsigned char *pBbuf, 
			IN int iWidthPix, 
			IN int iHeightPix
			);
/*
  *	Convert reading BMP file data to normal order, Including BMP 8bits and BMP24bits.
  *
  *	Parameters:
  *	
  *	iBuffer:	BMP image file data buffer;
  *	iWidth:	image width;
  *	iHeight:	image height;
  *	iBits:	bitscount, such as 8,24
  *
  */
int 
BMPBufBottomToUp(
							INOUT unsigned char*pBuffer, 
							IN	int iWidth, 
							IN	int iHeight, 
							IN	int iBits
							);



#endif 	//end __ImgReadBMP_H