原理: 浮雕通过勾画图像轮廓和降低周围像素颜色值，从而生产具有凹凸感的浮雕效果。

1.添加头文件, 并定义相关宏和结构体

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <jpeglib.h>

#define JpegStdError jpeg_std_error
#define JpegCreateDecompress jpeg_create_decompress
#define JpegCreateCompress jpeg_create_compress
#define JpegStdioSrc jpeg_stdio_src
#define JpegReadHeader jpeg_read_header
#define JpegStartDecompress jpeg_start_decompress
#define ScanLine output_scanline
#define NextLine next_scanline
#define JpegReadLine jpeg_read_scanlines
#define JpegFinishDecompress jpeg_finish_decompress
#define JpegDestroyDecompress jpeg_destroy_decompress
#define JpegStdioDest jpeg_stdio_dest
#define JpegSetDefault jpeg_set_defaults
#define JpegSetQuality jpeg_set_quality
#define JpegStartCompress jpeg_start_compress
#define JpegWriteLine jpeg_write_scanlines
#define JpegFinishCompress jpeg_finish_compress
#define JpegDestroyCompress jpeg_destroy_compress

typedef JSAMPARRAY JpegArray;
typedef FILE *FilePtr;
typedef struct jpeg_compress_struct JpegComp;
typedef struct jpeg_decompress_struct JpegDecomp;
typedef struct jpeg_error_mgr JpegErrMgr;
typedef struct ImagePicData ImagePicData;
typedef struct ImageRGBAColor ImageRGBAColor;
typedef struct ImagePicPos ImagePicPos;

struct ImagePicData
{
    unsigned char FName[256];
    FilePtr FPtr;
    int Width;
    int Height;
    int BitDepth;
    int Flag;
    int ColType;
    unsigned char *RGBA;
};

struct ImageRGBAColor
{
    short r;
    short g;
    short b;
    short a;
};

2.实现调和浮雕的函数

int EmbossImage(ImagePicData *ImageData, unsigned char *ImageXcgData, short offset)
{
    ImagePicData ImageTempData;
    ImageRGBAColor RGBAColor;
    int Pos = 0;
    int i, j;

    ImageTempData.RGBA = ImageXcgData;

    //printf("for[i]循环开始\n");

    for(i = 0; i < ImageData->Height-1; i++)
    {
        for(j = 0; j < ImageData->Width-1; j++)
        {

            RGBAColor.r = 4*ImageData->RGBA[((i)*ImageData->Width+(j))*4+0] - ImageData->RGBA[((i-1)*ImageData->Width+(j-1))*4+0] - ImageData->RGBA[((i-1)*ImageData->Width+(j+1))*4+0] - ImageData->RGBA[((i+1)*ImageData->Width+(j-1))*4+0] - ImageData->RGBA[((i+1)*ImageData->Width+(j+1))*4+0];
            RGBAColor.g = 4*ImageData->RGBA[((i)*ImageData->Width+(j))*4+1] - ImageData->RGBA[((i-1)*ImageData->Width+(j-1))*4+1] - ImageData->RGBA[((i-1)*ImageData->Width+(j+1))*4+1] - ImageData->RGBA[((i+1)*ImageData->Width+(j-1))*4+1] - ImageData->RGBA[((i+1)*ImageData->Width+(j+1))*4+1];
            RGBAColor.b = 4*ImageData->RGBA[((i)*ImageData->Width+(j))*4+2] - ImageData->RGBA[((i-1)*ImageData->Width+(j-1))*4+2] - ImageData->RGBA[((i-1)*ImageData->Width+(j+1))*4+2] - ImageData->RGBA[((i+1)*ImageData->Width+(j-1))*4+2] - ImageData->RGBA[((i+1)*ImageData->Width+(j+1))*4+2];

            RGBAColor.r += offset;
            RGBAColor.g += offset;
            RGBAColor.b += offset;


            if(RGBAColor.r < 0) RGBAColor.r = 0;
            else if(RGBAColor.r > 255) RGBAColor.r = 255;
            if(RGBAColor.g < 0) RGBAColor.g = 0;
            else if(RGBAColor.g > 255) RGBAColor.g = 255;
            if(RGBAColor.b < 0) RGBAColor.b = 0;
            else if(RGBAColor.b > 255) RGBAColor.b = 255;

            ImageTempData.RGBA[((i)*ImageData->Width+(j))*4+0] = RGBAColor.r;
            ImageTempData.RGBA[((i)*ImageData->Width+(j))*4+1] = RGBAColor.g;
            ImageTempData.RGBA[((i)*ImageData->Width+(j))*4+2] = RGBAColor.b;
        }
    }

    memcpy(ImageData->RGBA, ImageTempData.RGBA, ImageData->Width*ImageData->Height*4);

    return 0;
}

3.读写图片

参见《C语言实现色彩平衡算法》

4.添加主函数

int main(int argc, char **argv)
{
    ImagePicData PicData;
    int a = 127;
    char RGBAData[16*300*300];
    char RGBATempData[16*300*300];
    char JpegInputName[256];
    char JpegOutputName[256];

    memset(&PicData, 0x00, sizeof(PicData));
    memset(JpegInputName, 0x00, sizeof(JpegInputName));
    memset(JpegOutputName, 0x00, sizeof(JpegOutputName));

    if(argc != 4)
    {
        printf("入参个数错误!\n");
        return -1;
    }

    strncpy(JpegInputName, argv[1], 255);
    strncpy(JpegOutputName, argv[2], 255);

    PicData.RGBA = RGBAData;

    a = atoi(argv[3]);

    strcpy(PicData.FName, JpegInputName);

    LoadJPG(&PicData);

    strcpy(PicData.FName, JpegOutputName);

    EmbossImage(&PicData, RGBATempData, a);

    CreateJPG(&PicData);

    return 0;
}

5.编译运行

$ gcc -o examle examle.c -L$HOME/local/prior/lib -ljpeg
$ ./examle a.jpg b.jpg 150

6.运行结果

原图

986cc94c21f05aa13c748e325ba49d10.jpg

效果

986cc95X.jpg