用C语言实现图像的线性灰度变换

彭军
4
2010 年 4 月 30 日
图像线性灰度变换
#ifndef _BITMAP_H_ #define _BITMAP_H_
#include <stdio.h>
#define GET_B(bmp,i,j) ( *( bmp->ptr + bmp->line_width * i + j ) ) #define GET_G(bmp,i,j) ( *( bmp->ptr + bmp->line_width * i + j + 1 ) ) #define GET_R(bmp,i,j) ( *( bmp->ptr + bmp->line_width * i + j + 2 ) ) #define SET_B(bmp,i,j,v) ( *( bmp->ptr + bmp->line_width * i + j ) = v ) #define SET_G(bmp,i,j,v) ( *( bmp->ptr + bmp->line_width * i + j + 1 ) = v ) #define SET_R(bmp,i,j,v) ( *( bmp->ptr + bmp->line_width * i + j + 2 ) = v ) #define IS8BITS(bmp) ( ( bmp->ptr != NULL && bmp->bit_count == 8 )? 1 : 0 ) #define IS24BITS(bmp) ( ( bmp->ptr != NULL && bmp->bit_count == 24 ) ? 1 : 0 ) #define ISEMPTY(bmp) ( ( bmp->ptr == NULL ) ? 1 : 0 ) #define LIM255(v) ( ( v > 255 ) ? 255 : v ) #define LIMTO0(v) ( ( v < 0 ) ? 0 : v )
typedef unsigned char BYTE; typedef unsigned short WORD; typedef unsigned long DWORD;
typedef struct tagBitmap
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彭军
5
2010 年 4 月 30 日
图像线性灰度变换
{ BYTE* ptr; BYTE* palette; DWORD width; DWORD height; WORD bit_count; DWORD line_width; WORD pal_length; }Bitmap;
fwrite( &dw, 4, 1, fp ); //write the biSize dw = 40; fwrite( &dw, 4, 1, fp ); //write the biWidth dw = bmp->width; fwrite( &dw, 4, 1, fp ); //write the biHeight dw = bmp->height; fwrite( &dw, 4, 1, fp ); //write the biPlanes
save_bitmap( argv[2], bmp );
free_bitmap( bmp ); free( bmp );
return 0; } =================================================== Bitmap.h 的全部程序：
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//read the color palette if the bitmap have a color palette bmp->pal_length = off_bits - 54; if( bmp->pal_length == 0 ) { bmp->palette = 0; } else { bmp->palette = (BYTE*)malloc( bmp->pal_length * sizeof(BYTE) ); if( !bmp->palette ) return;
2010
图像线性灰度变换
用 C 语言实现
用 C 语言实现位图的线性灰度变换
彭军 利达光电股份有限公司 2010/5/6
2010 年 4 月 30 日
Hale Waihona Puke 图像线性灰度变换/* File Name: lintrans.c
Description: using the linear gray tranform to a 8-bits bitmap Author: */ Peng Jun
利达光电股份有限公司 |
彭军
9
2010 年 4 月 30 日
图像线性灰度变换
fread( bmp->ptr, line_width * height, 1, fp ); //close the file fclose( fp ); }
void save_bitmap( const char *filename, Bitmap *bmp ) { FILE *fp = 0; DWORD dw = 0; WORD w = 0; //open the file for writing if( ( fp = fopen( filename, "wb" ) ) == NULL ) { printf("can not create the bitmap : %s\n", filename ); return; }
if( argc == 3 ) { a = 1.0; b = 0.0; }
利达光电股份有限公司 |
彭军
2
2010 年 4 月 30 日
图像线性灰度变换
if( argc == 5 ) { a = atof( argv[3] ); b = atof( argv[4] ); }
if( argc != 3 && argc != 5 ) { printf("Usage: lintrans <img_src> <img_dst> <a> <b>\n"); free( bmp ); return -1; }
利达光电股份有限公司 |
彭军
8
2010 年 4 月 30 日
图像线性灰度变换
fseek( fp, 54, 0 ); fread( bmp->palette, bmp->pal_length * sizeof(BYTE), 1, fp ); }
//set the memeber of the structure Bitmap line_width = ( width * bit_count + 31 ) / 32 * 4; bmp->line_width = line_width; bmp->width = width; bmp->height = height; bmp->bit_count = bit_count; //allocate memory for the pixel of the bitmap bmp->ptr = (BYTE*)malloc( line_width * height * sizeof(BYTE) ); if( !bmp->ptr ) { printf("can not allocate memory for the bitmap.\n"); bmp->width = 0; bmp->height = 0; bmp->bit_count = 0; return; } //read the pixel matrix from the bitmap fseek( fp, off_bits, 0 );
#include <stdio.h> #include <stdlib.h> #include "Bitmap.h"
int main(int argc, char *argv[]) { Bitmap *bmp = (Bitmap*)malloc( sizeof(Bitmap) ); double a = 0.0, b = 0.0, f = 0.0; DWORD i = 0, j = 0; BYTE g = 0;
for( i = 0; i < bmp->height; i++ ) { for( j = 0; j < bmp->width; j++ ) { g = GET_B( bmp, i, j ); f = g * a + b; f = LIMTO0( f ); f = LIM255( f ); SET_B( bmp, i, j, f ); } }
#include "Bitmap.h"
void load_bitmap( const char *filename, Bitmap *bmp ) { FILE *fp = 0; DWORD off_bits = 0, width = 0, height = 0, line_width = 0; WORD bit_count = 0;
//write the bfType w = 19778; fwrite( &w, 2, 1, fp ); //write the bfSize dw = 14;
利达光电股份有限公司 |
彭军
10
2010 年 4 月 30 日
图像线性灰度变换