彩屏图像取模,BMP图像提取程序示例

陪她去流浪 桃子 2013年04月21日 编辑 阅读次数:6316

由于屏幕的多种类性, 我始终没有使用市面上的那种取模软件, 我始终感觉数据可能不对.

因为我的屏幕的要求比例是R:G:B(5:6:5),16位色,一个像素2个字节保存,所以总觉得应该自己写 一个来做这种转换工作的软件.

今天写了个小程序,在彩屏上显示出来的效果很好. 程序是为我的屏幕的数据类型量身生成的, 写在这里只是保存一下,不然久了,我又不知道代码之前的版本, 或是又找不到了.

程序解析BMP图像数据到点阵字模(仅支持24位位深的BMP位图,现在大都是这种),生成是数据 是16位的无符号字符型数据数组.直接调用写进屏幕即可显示出来.

代码分两个文件:bmconv.h,bmconv.c

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//bmconv.h
#ifndef __BMCONV_H__
#define __BMCONV_H__

#pragma pack(push,1)

//位图文件头数据
typedef struct _BITMAP_FILE_HEADER{
    unsigned char signature[2];         //00~01:文件头签名字节,仅检测'BM'序
    unsigned long file_size;            //02~05:整个文件的大小
    unsigned long _reserved1;           //06~09:保留4字节,必须为0
    unsigned long data_offset;          //0A~0D:位图数据距文件开始的偏移
}BITMAP_FILE_HEADER;

//图像信息头数据
typedef struct _BITMAP_INFO_HEADER{
    unsigned long header_size;          //0E~11:位图信息头的长度,根据文件判断
    unsigned long width;                //12~15:位图宽度,像素为单位
    unsigned long height;               //16~19:位图高度,像素为单位
    unsigned short planes;              //1A~1B:位图的面数,该值总是1
    unsigned short bpp;                 //1C~1D:位深:1,4,8,16,24,32
    unsigned long compress;             //1E~21:压缩说明
    unsigned long data_size;            //22~25:数据大小
    unsigned long hresolution;          //26~29:水平分辨率
    unsigned long vresolution;          //2A~2D:垂直分辨率
    unsigned long colors;               //2E:31:使用的颜色数
    unsigned long colors_important;     //重要的颜色数
}BITMAP_INFO_HEADER;

//颜色表
typedef struct _RGBQUAD{
    unsigned char blue;
    unsigned char green;
    unsigned char red;
    unsigned char _reserved;
}BITMAP_RGB_QUAD;

//由图像信息头+颜色表组成的图像信息
typedef struct _BITMAP_INFO{
    BITMAP_INFO_HEADER bmih;
    BITMAP_RGB_QUAD bmcolor;
}BITMAP_INFO;

#pragma pack(pop)

#endif//!__BMCONV_H__
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//bmconv.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "bmconv.h"

/*************************************************************************
文件名称:bmconv.c/bmconv.h
文件功能:BMP提取到点阵RGB显示
创建时间:2013-04-20
文件作者:女孩不哭
文件版本:1.0
文件说明:专用
*************************************************************************/

__inline unsigned int myrgb(int a)
{
    unsigned short b = (a&0xff)>>3;
    unsigned short g = ((a&0xff00)>>10);
    unsigned short r = ((a&0xff0000)>>19);
    unsigned int rgb = (b|(g<<5)|(r<<11));
    return rgb;
}

int main(void)
{
    char file[260];
    char file_out[260];
    char* pstr = NULL;
    unsigned char* buffer=NULL;
    char*  outout_data = NULL;

    BITMAP_FILE_HEADER bmfh={0};
    BITMAP_INFO_HEADER bmih={0};
    FILE* fpin = NULL;
    FILE* fpout = NULL;
    size_t size = 0;
    size_t file_size;

    printf("输入BMP文件打开路径:");
    fgets(file,sizeof(file),stdin);
    pstr = strrchr(file,'\n');
    if(pstr) *pstr = 0;
    printf("输入BMP文件保存路径:");
    fgets(file_out,sizeof(file_out),stdin);
    pstr = strrchr(file_out,'\n');
    if(pstr) *pstr = 0;

    fpin = fopen(file,"rb");
    if(fpin==NULL){
        fprintf(stderr,"打开输入文件错误!\n");
        return 1;
    }
    fpout = fopen(file_out,"wb");
    if(fpout==NULL){
        fprintf(stderr,"打开输出文件错误!\n");
        fclose(fpin);
        return 1;
    }
    fseek(fpin,0,SEEK_END);
    file_size = ftell(fpin);
    fseek(fpin,0,SEEK_SET);
    size = fread(&bmfh,1,sizeof(bmfh),fpin);
    if(size != sizeof(bmfh)){
        fclose(fpin);
        fprintf(stderr,"读取文件头时错误!\n");
        return 1;
    }
    if(bmfh.signature[0]!='B' || bmfh.signature[1]!='M'){
        fclose(fpin);
        fprintf(stderr,"不是BMP文件!\n");
        return 1;
    }
    printf(
        "文件头结构体大小:%d\n"
        "文件头签名:\'BM\'\n"
        "文件大小:%u bytes\n"
        "保留4字节值:%u\n"
        "位图数据距文件开始的偏移:%u\n\n",(long)sizeof(bmfh),
        bmfh.file_size,bmfh._reserved1,bmfh.data_offset);
    size = fread(&bmih,1,sizeof(bmih),fpin);
    if(size != sizeof(bmih)){
        fclose(fpin);
        fprintf(stderr,"读取图像信息头错误!\n");
        return 1;
    }
    printf(
        "图像信息头结构体大小:%d\n"
        "图像信息头大小:%d bytes\n"
        "位图宽度: %u 像素\n"
        "位图高度: %u 像素\n"
        "位图面数: %d 面\n"
        "位深: %d bpp\n"
        "压缩说明: %d\n"
        "位图数据大小: %u bytes\n"
        "水平分辨率: %u 像素/米\n"
        "垂直分辨率: %u 像素/米\n"
        "使用的颜色数: %u\n"
        "重要的颜色数: %u\n\n",(long)sizeof(bmih),
        bmih.header_size,bmih.width,bmih.height,bmih.planes,bmih.bpp,bmih.compress,
        bmih.data_size,bmih.hresolution,bmih.vresolution,bmih.colors,bmih.colors_important);
    //检测文件数据大小是否符合文件头
    size = bmih.width*3;
    size += size%4==0?0:4-size%4;
    size *= bmih.height;
    if(size != file_size-bmfh.data_offset){
        fprintf(stderr,"位图的数据量与文件头所标识的数据量的长度不一致!\n");
        fclose(fpin);
        return 1;
    }
    if(bmih.bpp != 24){
        fprintf(stderr,"不是24位位深的BMP位图,不被支持!\n");
        fclose(fpin);
        return 1;
    }
    buffer=(unsigned char*)malloc(size);
    //printf("buffer大小:%d\n",size);
    if(buffer==NULL){
        fprintf(stderr,"分配文件缓冲区时出错!\n");
        fclose(fpin);
        return 1;
    }
    if(size != fread(buffer,1,size,fpin)){
        fprintf(stderr,"读取位图数据时读取的长度不一致!\n");
        free(buffer);
        fclose(fpin);
        return 1;
    }
    fclose(fpin);
    //交换上下内存
    for(;;){
        int bytes_line = size/bmih.height;
        int rows = bmih.height/2;
        int it=0;
        unsigned char* tmp = (unsigned char*)malloc(bytes_line);
        while(it<rows){
            memcpy(tmp,buffer+bytes_line*it,bytes_line);
            memcpy(buffer+bytes_line*it,buffer+(bmih.height-1-it)*bytes_line,bytes_line);
            memcpy(buffer+(bmih.height-1-it)*bytes_line,tmp,bytes_line);
            it++;
        }
        free(tmp);
        break;
    }
    //总像素点个数(一个像素3个字节),3个字节转换成2个字节,2个字节转成字符串需要7个字节空间(0x0000,)
    //每行后面1个换行符(每行16个"0x0000,",2个字节),字符串开始的结束的字符串("unsigned char image[] = {" + 换行 + "};"
    for(;;){
        size_t pixels = bmih.width*bmih.height;
        size_t str_length = pixels*7;
        size_t crlf_count = pixels/16 + (pixels%16==0?0:1);
        size_t prefix_length = sizeof("unsigned short image[] = {\r\n")-1 + sizeof("};\r\n")-1;
        size_t total = str_length+crlf_count*2+prefix_length+1;
        outout_data = (char*)malloc(total);
        //printf("str:%d,crlf:%d,prefix:%d,total::%d\n",str_length,crlf_count*2,prefix_length,total);
        if(outout_data == NULL){
            fprintf(stderr,"申请保存数据用的缓冲区失败!\n");
            free(buffer);
            return 1;
        }
        printf("正在生成数据...\n");
        for(;;){
            char* ptr = outout_data;
            unsigned char* pbuf = buffer;
            int count = 0;
            unsigned long lines;
            int skip = (bmih.width*3%4)?(4-bmih.width*3%4):0;
            int len;
            len=sprintf(ptr,"unsigned short image[] = {\r\n");
            ptr += len;
            for(lines=0;lines<bmih.height;){
                len=sprintf(ptr,"0x%04X,",(unsigned short)myrgb(*(int*)pbuf));
                ptr += len;
                count++;
                if(count == 16){
                    count = 0;
                    len=sprintf(ptr,"\r\n");
                    ptr += len;
                }
                pbuf += 3;
                if((unsigned long)pbuf-(unsigned long)buffer-lines*skip == bmih.width*3*(lines+1)){
                    pbuf += skip;
                    lines++;
                }
            }
            if(count==0){
                ptr -= 3;
                len=sprintf(ptr,"\r\n");

                ptr+=len;
            }else{
                --ptr;
                len=sprintf(ptr,"\r\n");
                ptr += len;
            }
            len=sprintf(ptr,"};\r\n");
            ptr += len;
            printf("生成成功!\n");
            //printf("结尾指针:pbuf-buffer=%d,ptr-outout_data=%d\n",pbuf-buffer,ptr-outout_data);
            len=fwrite(outout_data,1,(unsigned long)ptr-(unsigned long)outout_data,fpout);
            if(len != (unsigned long)ptr-(unsigned long)outout_data){
                fprintf(stderr,"写入数据的长度不等于待写入的要求!\n");
            }else{
                printf("已全部保存到文件!\n");
            }
            fclose(fpout);
            free(buffer);
            free(outout_data);
            break;
        }
        break;
    }
    return 0;
}

软件运行过程:

bmconv.jpg

最终生成的数据像这种:

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unsigned short image[] = {
0xDF9F,0xC75F,0xA71F,0x7EBF,0x667F,0x4E3F,0x3E1F,0x35FF,
0x35FF,0x35FF,0x35FF,0x35FF,0x35FF,0x35FF,0x35FF,0x35FF,
0x463F,0x461F,0x3E1F,0x6E7F,0xA6FF,0xCF7F,0xDF9F,0xC75F,
0x35FF,0x35FF,0x35FF,0x35FF,0x35FF,0x35FF,0x35FF,0x35FF,
0x35FF,0x35FF,0x35FF,0x35FF,0x35FF,0x35FF,0x35FF,0x35FF,
0x35FF,0x35FF,0x35FF,0x35FF,0x35FF,0x35FF,0x35FF,0x35FF,
0x35FF,0x35FF,0x35FF,0x35FF,0x35FF,0x35FF,0x35FF,0x35FF,
0x35FF,0x35FF,0x35FF,0x35FF,0x35FF,0x35FF,0x35FF,0x35FF,
0x35FF,0x35FF,0x35FF,0x35FF,0x35FF,0x35FF,0x35FF,0x35FF
};

源代码及程序: bmconv.7z

哈哈,自己写的软件,用得放心.

标签:代码片段 · 嵌入式 · 位图