v3

.vscode/c_cpp_properties.json

@@ -0,0 +1,20 @@
+{
+    "configurations": [
+        {
+            "name": "Win32",
+            "includePath": [
+                "${workspaceFolder}/**"
+            ],
+            "defines": [
+                "_DEBUG",
+                "UNICODE",
+                "_UNICODE"
+            ],
+            "compilerPath": "C:\\MinGW\\bin\\gcc.exe",
+            "cStandard": "c11",
+            "cppStandard": "gnu++14",
+            "intelliSenseMode": "windows-gcc-x86"
+        }
+    ],
+    "version": 4
+}

.vscode/settings.json

@@ -0,0 +1,46 @@
+{
+    "files.associations": {
+        "array": "cpp",
+        "atomic": "cpp",
+        "*.tcc": "cpp",
+        "cctype": "cpp",
+        "clocale": "cpp",
+        "cmath": "cpp",
+        "cstdarg": "cpp",
+        "cstddef": "cpp",
+        "cstdint": "cpp",
+        "cstdio": "cpp",
+        "cstdlib": "cpp",
+        "cwchar": "cpp",
+        "cwctype": "cpp",
+        "deque": "cpp",
+        "unordered_map": "cpp",
+        "vector": "cpp",
+        "exception": "cpp",
+        "algorithm": "cpp",
+        "functional": "cpp",
+        "iterator": "cpp",
+        "memory": "cpp",
+        "memory_resource": "cpp",
+        "numeric": "cpp",
+        "random": "cpp",
+        "string": "cpp",
+        "system_error": "cpp",
+        "tuple": "cpp",
+        "type_traits": "cpp",
+        "utility": "cpp",
+        "fstream": "cpp",
+        "initializer_list": "cpp",
+        "iosfwd": "cpp",
+        "iostream": "cpp",
+        "istream": "cpp",
+        "limits": "cpp",
+        "new": "cpp",
+        "ostream": "cpp",
+        "sstream": "cpp",
+        "stdexcept": "cpp",
+        "streambuf": "cpp",
+        "cinttypes": "cpp",
+        "typeinfo": "cpp"
+    }
+}

bmp_copy_demo.c

@@ -85,15 +85,11 @@ void bmpWrite(const char* name, const uch* raw_img,
         for(unsigned i = 0; i < width; ++i) {
             uint32_t idx = j*width +i;
             if(bits == 24) { // RGBˆDƬ
-                fwrite((char*)&raw_img[idx*3 +2],
-                    sizeof(char), sizeof(uch), pFile);
-                fwrite((char*)&raw_img[idx*3 +1],
-                    sizeof(char), sizeof(uch), pFile);
-                fwrite((char*)&raw_img[idx*3 +0],
-                    sizeof(char), sizeof(uch), pFile);
+                fwrite((char*)&raw_img[idx*3 +2], sizeof(char), sizeof(uch), pFile);
+                fwrite((char*)&raw_img[idx*3 +1], sizeof(char), sizeof(uch), pFile);
+                fwrite((char*)&raw_img[idx*3 +0], sizeof(char), sizeof(uch), pFile);
             } else if(bits == 8) { // »ÒëAˆD
-                fwrite((char*)&raw_img[idx],
-                    sizeof(char), sizeof(uch), pFile);
+                fwrite((char*)&raw_img[idx], sizeof(char), sizeof(uch), pFile);
             }
         }
         // Œ¦ýR4byte
@@ -137,15 +133,11 @@ void bmpRead(const char* name, uch** raw_img,
         for(unsigned i = 0; i < *width; ++i) {
             uint32_t idx = j*(*width)+i;
             if(*bits == 24) { // RGBˆDƬ
-                fread((char*)&(*raw_img)[idx*3 +2], 
-                    sizeof(char), sizeof(uch), pFile);
-                fread((char*)&(*raw_img)[idx*3 +1], 
-                    sizeof(char), sizeof(uch), pFile);
-                fread((char*)&(*raw_img)[idx*3 +0], 
-                    sizeof(char), sizeof(uch), pFile);
+                fread((char*)&(*raw_img)[idx*3 +2], sizeof(char), sizeof(uch), pFile);
+                fread((char*)&(*raw_img)[idx*3 +1], sizeof(char), sizeof(uch), pFile);
+                fread((char*)&(*raw_img)[idx*3 +0], sizeof(char), sizeof(uch), pFile);
             } else if(*bits == 8) { // »ÒëAˆD
-                fread((char*)&(*raw_img)[idx], 
-                    sizeof(char), sizeof(uch), pFile);
+                fread((char*)&(*raw_img)[idx], sizeof(char), sizeof(uch), pFile);
             }
         }
         fseek(pFile , (long)alig , SEEK_CUR);

idk.c

@@ -0,0 +1,181 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <inttypes.h>
+typedef unsigned char uch;
+
+// ™n°¸½Y˜‹
+#pragma pack(2)
+struct BmpFileHeader {
+    uint16_t bfTybe;
+    uint32_t bfSize;
+    uint16_t bfReserved1;
+    uint16_t bfReserved2;
+    uint32_t bfOffBits;
+};
+struct BmpInfoHeader {
+    uint32_t biSize;
+    uint32_t biWidth;
+    uint32_t biHeight;
+    uint16_t biPlanes; // 1=defeaul, 0=custom
+    uint16_t biBitCount;
+    uint32_t biCompression;
+    uint32_t biSizeImage;
+    uint32_t biXPelsPerMeter; // 72dpi=2835, 96dpi=3780
+    uint32_t biYPelsPerMeter; // 120dpi=4724, 300dpi=11811
+    uint32_t biClrUsed;
+    uint32_t biClrImportant;
+};
+#pragma pack()
+
+
+void bmpWrite(const char* name, const uch* raw_img,
+    uint32_t width, uint32_t height, uint16_t bits, float radio_w, float radio_h)
+{
+    if(!(name && raw_img)) {
+        perror("Error bmpWrite.");
+        return;
+    }
+    // ™n°¸ÙYÓ<59>
+    struct BmpFileHeader file_h = {
+        .bfTybe=0x4d42,
+        .bfReserved1=0,
+        .bfReserved2=0,
+        .bfOffBits=54,
+    };
+    uint32_t new_width = width*radio_w;
+    uint32_t new_height = height*radio_h;
+    file_h.bfSize = file_h.bfOffBits + new_width*new_height * bits/8;
+    if(bits==8) {file_h.bfSize+= 1024, file_h.bfOffBits+= 1024;}
+    // ˆDƬÙYÓ<59>
+    struct BmpInfoHeader info_h = {
+        .biSize=40,
+        .biPlanes=1,
+        .biCompression=0,
+        .biXPelsPerMeter=0,
+        .biYPelsPerMeter=0,
+        .biClrUsed=0,
+        .biClrImportant=0,
+    };
+    info_h.biWidth = new_width;
+    info_h.biHeight = new_height;
+    info_h.biBitCount = bits;
+    info_h.biSizeImage = new_width*new_height * bits/8;
+    if(bits == 8) {info_h.biClrUsed=256;}
+    // Œ‘Èë™nî^
+    FILE *pFile = NULL;
+    // pFile = fopen(name,"wb+");
+    fopen_s(&pFile, name,"wb+");
+    if(!pFile) {
+        perror("Error opening file.");
+        return;
+    }
+    fwrite((char*)&file_h, sizeof(char), sizeof(file_h), pFile);
+    fwrite((char*)&info_h, sizeof(char), sizeof(info_h), pFile);
+    // Œ‘Õ{É«±P
+    if(bits == 8) {
+        for(unsigned i = 0; i < 256; ++i) {
+            uch c = i;
+            fwrite((char*)&c, sizeof(char), sizeof(uch), pFile);
+            fwrite((char*)&c, sizeof(char), sizeof(uch), pFile);
+            fwrite((char*)&c, sizeof(char), sizeof(uch), pFile);
+            fwrite("", sizeof(char), sizeof(uch), pFile);
+        }
+    }
+    // Œ‘ÈëˆDƬÙYÓ<59>
+    size_t alig = ((new_width*bits/8)*3) % 4;
+    for(int j = height-1; j >= 0; --j) {
+        for(unsigned i = 0; i < new_width; ++i) {
+            uint32_t idx = j*new_width +i;
+            if(bits == 24) { // RGBˆDƬ
+                fwrite((char*)&raw_img[idx*3 +2], sizeof(char), sizeof(uch), pFile);
+                fwrite((char*)&raw_img[idx*3 +1], sizeof(char), sizeof(uch), pFile);
+                fwrite((char*)&raw_img[idx*3 +0], sizeof(char), sizeof(uch), pFile);
+            } else if(bits == 8) { // »ÒëAˆD
+                fwrite((char*)&raw_img[idx], sizeof(char), sizeof(uch), pFile);
+            }
+        }
+        // Œ¦ýR4byte
+        for(size_t i = 0; i < alig; ++i) {
+            fwrite("", sizeof(char), sizeof(uch), pFile);
+        }
+    }
+    fclose(pFile);
+}
+void bmpRead(const char* name, uch** raw_img,
+    uint32_t* width, uint32_t* height, uint16_t* bits)
+{
+    if(!(name && raw_img && width && height && bits)) {
+        perror("Error bmpRead.");
+        return;
+    }
+    // ™n°¸ÙYÓ<59>
+    struct BmpFileHeader file_h;
+    // ˆDƬÙYÓ<59>
+    struct BmpInfoHeader info_h;
+    // ×xÈ¡™nî^
+    FILE *pFile = NULL;
+    // pFile = fopen(name, "rb+");
+    fopen_s(&pFile, name, "rb+");
+    if(!pFile) {
+        perror("Error opening file.");
+        return;
+    }
+    fread((char*)&file_h, sizeof(char), sizeof(file_h), pFile);
+    fread((char*)&info_h, sizeof(char), sizeof(info_h), pFile);
+    // ×xÈ¡éLŒ’
+    *width = info_h.biWidth;
+    *height = info_h.biHeight;
+    *bits = info_h.biBitCount;
+    size_t ImgSize = ((size_t)*width) * ((size_t)*height) * 3;
+    *raw_img = (uch*)calloc(ImgSize, sizeof(uch));
+    // ×xÈ¡×xƬÙYÓ<59>ÞDRAW™nÙYÓ<59>
+    fseek(pFile, file_h.bfOffBits, SEEK_SET);
+    size_t alig = ((info_h.biWidth*info_h.biBitCount/8)*3) % 4;
+    for(int j = *height-1; j >= 0; --j) {
+        for(unsigned i = 0; i < *width; ++i) {
+            uint32_t idx = j*(*width)+i;
+            if(*bits == 24) { // RGBˆDƬ
+                fread((char*)&(*raw_img)[idx*3 +2], sizeof(char), sizeof(uch), pFile);
+                fread((char*)&(*raw_img)[idx*3 +1], sizeof(char), sizeof(uch), pFile);
+                fread((char*)&(*raw_img)[idx*3 +0], sizeof(char), sizeof(uch), pFile);
+            } else if(*bits == 8) { // »ÒëAˆD
+                fread((char*)&(*raw_img)[idx], sizeof(char), sizeof(uch), pFile);
+            }
+        }
+        fseek(pFile , (long)alig , SEEK_CUR);
+    }
+    fclose(pFile);
+}
+
+// ˆDÏñ½Y˜‹
+typedef struct Imgraw {
+    uint32_t width, height;
+    uint16_t bits;
+    uch* data;
+} Imgraw;
+void Imgraw_Read(const Imgraw* _this, const char* name) {
+    const Imgraw* p = _this;
+    bmpRead(name, &p->data, &p->width, &p->height, &p->bits);
+}
+void Imgraw_Writ(const Imgraw* _this, const char* name, float radio_w, float radio_h) {
+    const Imgraw* p = _this;
+    bmpWrite(name, p->data, p->width, p->height, p->bits, radio_w, radio_h);
+}
+/*==============================================================*/
+int main(int argc, char const *argv[]) {
+    float radio_w, radio_h;
+    printf("Enter a radio of width :") ;
+    scanf("%f", &radio_w);
+    printf("Enter a radio of height :") ;
+    scanf("%f", &radio_h);
+    printf("%f :: %f", radio_w, radio_h);
+
+    // ½¨˜‹
+    Imgraw img = {0, 0, 0, NULL};
+    // ×xˆD
+    Imgraw_Read(&img, "./input/bw2x1.bmp");
+    // Œ‘ˆD
+    Imgraw_Writ(&img, "./output/bw2x1(output).bmp", radio_w, radio_h);
+    return 0;
+}
+/*==============================================================*/

test.cpp

@@ -1,134 +0,0 @@
-#include<stdio.h>
-#include<stdlib.h>
-#include<string.h>
-#include <stdlib.h>
-#pragma pack(1)//必须在结构体定义之前使用,这是为了让结构体中各成员按1字节对齐
-// 文件头结构体
-typedef struct tagBITMAPFILEHEADER {
-	unsigned short bfType;	  // 保存图片类型，读取时需要注释掉，文本标识符只能单独进行读写 2
-	unsigned long bfSize;        // 文件大小 4
-	unsigned short bfReserved1;   // 保留，设置为0 2
-	unsigned short bfReserved2;   // 保留，设置为0 2
-	unsigned long bfOffBits;     // 从文件头到实际的图像数据之间的字节的偏移量(没调色板的话是54) 4
-} BITMAPFILEHEADER;
-
-//图像信息头结构体
-typedef struct tagBITMAPINFOHEADER {
-	unsigned long biSize;          // 此结构体的大小
-	unsigned long biWidth;         // 图像的宽
-	unsigned long biHeight;        // 图像的高
-	unsigned short biPlanes;        // 颜色平面数 恒为1
-	unsigned short biBitCount;      // 一像素所占的位数 Windows系统有8,16,24
-	unsigned long biCompression;   // 说明图象数据压缩的类型，0为不压缩
-	unsigned long biSizeImage;     // 图像大小, 值等于上面文件头结构中bfSize-bfOffBits
-	unsigned long biXPelsPerMeter; // 说明水平分辨率，用像素/米表示 一般为0
-	unsigned long biYPelsPerMeter; // 说明垂直分辨率，用像素/米表示 一般为0
-	unsigned long biClrUsed;       // 说明位图实际使用的彩色表中的颜色索引数（设为0的话，则说明使用所有调色板项）
-	unsigned long biClrImportant;  // 说明对图象显示有重要影响的颜色索引的数目 如果是0表示都重要
-} BITMAPINFOHEADER;
-
-void changeBmpFile(const char *src, const char *dest, double proportion) { //源文件名，目标文件名，放大或缩小比例
-	//1.源位图文件文件头和信息头
-	BITMAPFILEHEADER src_fileHeader;
-	BITMAPINFOHEADER src_infoHeader;
-
-	//2.目标位图文件文件头和信息头
-	BITMAPFILEHEADER dest_fileHeader;
-	BITMAPINFOHEADER dest_infoHeader;
-
-	//3.源位图文件对象&目标位图文件对象
-	FILE *src_file;
-	FILE *dest_file;
-
-	//4.源位图文件以读取(允许读和写)模式打开&目标位图文件以写入(只允许写)模式打开
-	src_file = fopen(src,"rb+");
-	dest_file = fopen(dest,"wb+");
-	if(src_file == NULL || dest_file == NULL) {
-		printf("文件打开失败，程序结束...\n");
-		exit(-1);
-	}
-
-	//5.读取源位图文件的标识符信息&文件头&信息头
-//	unsigned short fileIdentifier;
-//	fread(&fileIdentifier, sizeof(unsigned short), 1, src_file);
-	fread(&src_fileHeader, sizeof(BITMAPFILEHEADER), 1, src_file);
-	fread(&src_infoHeader, sizeof(BITMAPINFOHEADER), 1, src_file);
-
-	//6.一个位图文件的像素占据的内存空间 = 位数 ? 8，例如24位图一个像素占据3字节内存
-	int byte = src_infoHeader.biBitCount / 8;//表示每个像素由几个字节表示，对于24位位图文件来说，byte值为3
-
-	//7.获取源位图文件和目标位图文件的长宽(以像素为单位)以及尺寸(位图文件图像数据的字节大小)
-	unsigned long oldWidth, oldHeight, oldSize, newWidth, newHeight, newSize;
-
-	oldWidth = src_infoHeader.biWidth;
-	oldHeight = src_infoHeader.biHeight;
-	newWidth = ((int)(src_infoHeader.biWidth * proportion) + 3) / 4 * 4;//图像显示不出来原因在于图像长或宽不是4的倍数 下面这一步可以保证得到的宽高是4的倍数
-	newHeight = ((int)(src_infoHeader.biHeight * proportion) + 3) / 4 * 4;
-	printf("源位图文件高为：%d\n", oldHeight);
-	printf("源位图文件宽为：%d\n", oldWidth);
-	printf("目标位图文件高为：%d\n", newHeight);
-	printf("目标位图文件宽为：%d\n", newWidth);
-
-	oldSize = oldWidth * oldHeight * byte;
-	newSize = newWidth * newHeight * byte;
-
-	//8.sourceData是一个指针，指向源位图文件的图像存储数据
-	unsigned char *sourceData = (unsigned char*)malloc(oldSize);//该指针指向源位图文件图像数据的内存空间
-	fseek(src_file, 54, SEEK_SET);//使文件的指针指向文件的第55个字节
-	fread(sourceData, oldSize, 1, src_file);//将src_file中的图像数据存储到sourceData指向的内存空间
-
-	//9.目标位图文件文件头和信息头内容的更改
-	dest_fileHeader = src_fileHeader;
-	dest_infoHeader = src_infoHeader;
-
-	dest_fileHeader.bfSize = 54 + newSize;
-
-	dest_infoHeader.biWidth = newWidth;
-	dest_infoHeader.biHeight = newHeight;
-	dest_infoHeader.biSizeImage = newSize;
-
-//	fwrite(&fileIdentifier, sizeof(unsigned short), 1, dest_file);
-	fwrite(&dest_fileHeader, sizeof(BITMAPFILEHEADER), 1, dest_file);
-	fwrite(&dest_infoHeader, sizeof(BITMAPINFOHEADER), 1, dest_file);
-
-	//10.使用最邻近插值算法进行图片缩放
-	unsigned int x,y,X,Y;//源位图文件像素点宽高和目标位图文件像素点宽高
-	unsigned char *destData = (unsigned char*)malloc(newSize);//该指针指向目标位图文件图像数据的内存空间
-	unsigned char *sourceWhere, *destWhere;//修改像素的对应位置
-	for(Y = 0; Y < newHeight; Y++) {
-		y = Y / proportion;
-		destWhere = destData + Y * newWidth * byte;
-		sourceWhere = sourceData + y * oldWidth * byte;
-		for(X = 0; X < newWidth; X++) {
-			x = X / proportion;
-			memcpy(destWhere + X * byte, sourceWhere + x * byte, byte);
-		}
-	}
-
-	//11.写入数据并且释放内存&关闭文件流
-	fwrite(destData, newSize, 1, dest_file);
-	free(destData);
-	free(sourceData);
-	fclose(src_file);
-	fclose(dest_file);
-}
-
-int main(int argc,char *argv[]) {
-	printf("******位图文件压缩程序******\n");
-
-	// if(argc >= 4) {
-		// changeBmpFile(argv[1],argv[3],atoi(argv[2]) / 100.0);
-		// printf("缩放成功！\n");
-
-    changeBmpFile("./input/hello.bmp","./output/test(output).bmp",100.0 / 100.0);
-	printf("缩放成功！\n");
-	// } else if(argc == 1){
-	// 	printf("未传入参数，需要在控制台进行位图文件的压缩!!!");
-	// 	return 0;
-	// }else {
-	// 	printf("参数不足 ，程序结束...\n");
-	// 	exit(-1);
-	// }
-
-	return 0;
-}

transfer.c

@@ -1,8 +1,10 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <inttypes.h>
+#include <math.h>
 typedef unsigned char uch;
 
+
 // ™n°¸½Y˜‹
 #pragma pack(2)
 struct BmpFileHeader {
@@ -27,21 +29,16 @@ struct BmpInfoHeader {
 };
 #pragma pack()
 
+//辅助计算函数
+float linear_single(float x, float x1, float x2, float f1, float f2){
+    return floor(f1 * (x2 - x) / (x2 - x1) + f2 * (x - x1) / (x2 - x1));
+}
 
-void bmpWrite(const char* name, const uch* raw_img, uint32_t width, uint32_t height, uint16_t bits, const char* old_name, double radio)
-{
-    if(!(name && raw_img)) {
+void bmpWrite(const char* name, const uch* raw_img, uint32_t width, uint32_t height, uint32_t bits, float radio_w, float radio_h){
+    if(!(name && raw_img)){
         perror("Error bmpWrite.");
         return;
     }
-
-    unsigned long oldWidth, oldHeight, oldSize, newWidth, newHeight, newSize;
-    oldWidth = width;
-	oldHeight = height;
-
-    newWidth = ((int)(oldWidth * radio) + 3) / 4 * 4;//图像显示不出来原因在于图像长或宽不是4的倍数 保证得到的宽高是4的倍数
-	newHeight = ((int)(oldHeight * radio) + 3) / 4 * 4;
-
     // ™n°¸ÙYÓ<59>
     struct BmpFileHeader file_h = {
         .bfTybe=0x4d42,
@@ -49,8 +46,13 @@ void bmpWrite(const char* name, const uch* raw_img, uint32_t width, uint32_t hei
         .bfReserved2=0,
         .bfOffBits=54,
     };
-    file_h.bfSize = file_h.bfOffBits + newWidth*newHeight * bits/8;
+
+    uint32_t new_width = floor(width*radio_w);
+    uint32_t new_height = floor(height*radio_h);
+    file_h.bfSize = file_h.bfOffBits + new_width*new_height * bits/8;
     if(bits==8) {file_h.bfSize+= 1024, file_h.bfOffBits+= 1024;}
+
+
     // ˆDƬÙYÓ<59>
     struct BmpInfoHeader info_h = {
         .biSize=40,
@@ -61,10 +63,10 @@ void bmpWrite(const char* name, const uch* raw_img, uint32_t width, uint32_t hei
         .biClrUsed=0,
         .biClrImportant=0,
     };
-    info_h.biWidth = newWidth;
-    info_h.biHeight = newHeight;
-    info_h.biBitCount = bits;
-    info_h.biSizeImage = newWidth*newHeight * bits/8;
+    info_h.biWidth = new_width;
+    info_h.biHeight = new_height;
+    info_h.biBitCount = bits;// 多少位的圖
+    info_h.biSizeImage = new_width*new_height * bits/8;
     if(bits == 8) {info_h.biClrUsed=256;}
     // Œ‘Èë™nî^
     FILE *pFile = NULL;
@@ -86,43 +88,20 @@ void bmpWrite(const char* name, const uch* raw_img, uint32_t width, uint32_t hei
             fwrite("", sizeof(char), sizeof(uch), pFile);
         }
     }
+
+    // char newpixels[new_width*new_height];
+    unsigned char **newpixels=(unsigned char**)malloc(new_width*new_height*3);
+	
     // Œ‘ÈëˆDƬÙYÓ<59>
-    size_t alig = ((width*bits/8)*3) % 4;
-    for(int j = height-1; j >= 0; --j) {
-        for(unsigned i = 0; i < width; ++i) {
-            uint32_t idx = j*width +i;
+    size_t alig = ((new_width*bits/8)*3) % 4;
+    for(int j = new_height-1; j >= 0; --j) {
+        for(unsigned i = 0; i < new_width; ++i) {
+            uint32_t idx = j*new_width +i;
             if(bits == 24) { // RGBˆDƬ
                 fwrite((char*)&raw_img[idx*3 +2], sizeof(char), sizeof(uch), pFile);
                 fwrite((char*)&raw_img[idx*3 +1], sizeof(char), sizeof(uch), pFile);
                 fwrite((char*)&raw_img[idx*3 +0], sizeof(char), sizeof(uch), pFile);
-
-                // unsigned long oldWidth, oldHeight, oldSize, newWidth, newHeight, newSize;
-
-	            // oldWidth = width;
-	            // oldHeight = height;
-                unsigned char *sourceData = (unsigned char*)malloc(oldSize);//该指针指向源位图文件图像数据的内存空间
-	            fseek(old_name, 54, SEEK_SET);//使文件的指针指向文件的第55个字节
-	            fread(sourceData, oldSize, 1, old_name);//将src_file中的图像数据存储到sourceData指向的内存空间
-                
-                // newWidth = ((int)(oldWidth * radio) + 3) / 4 * 4;//图像显示不出来原因在于图像长或宽不是4的倍数 下面这一步可以保证得到的宽高是4的倍数
-	            // newHeight = ((int)(oldHeight * radio) + 3) / 4 * 4;
-
-                //10.使用最邻近插值算法进行图片缩放
-                unsigned int x,y,X,Y;//源位图文件像素点宽高和目标位图文件像素点宽高
-                unsigned char *destData = (unsigned char*)malloc(newSize);//该指针指向目标位图文件图像数据的内存空间
-                unsigned char *sourceWhere, *destWhere;//修改像素的对应位置
-                for(Y = 0; Y < newHeight; Y++) {
-                    y = Y / radio;
-                    destWhere = destData + Y * newWidth * 3;
-                    sourceWhere = sourceData + y * oldWidth * 3;
-                    for(X = 0; X < newWidth; X++) {
-                        x = X / radio;
-                        memcpy(destWhere + X * 3, sourceWhere + x * 3, 3);
-                    }
-                }
-
-            }
-            else if(bits == 8) { // 灰階圖
+            } else if(bits == 8) { // 灰階圖
                 fwrite((char*)&raw_img[idx], sizeof(char), sizeof(uch), pFile);
             }
         }
@@ -132,6 +111,8 @@ void bmpWrite(const char* name, const uch* raw_img, uint32_t width, uint32_t hei
         }
     }
     fclose(pFile);
+
+    free(newpixels); //記得釋放空間
 }
 void bmpRead(const char* name, uch** raw_img, uint32_t* width, uint32_t* height, uint16_t* bits)
 {
@@ -166,15 +147,11 @@ void bmpRead(const char* name, uch** raw_img, uint32_t* width, uint32_t* height,
         for(unsigned i = 0; i < *width; ++i) {
             uint32_t idx = j*(*width)+i;
             if(*bits == 24) { // RGBˆDƬ
-                fread((char*)&(*raw_img)[idx*3 +2], 
-                    sizeof(char), sizeof(uch), pFile);
-                fread((char*)&(*raw_img)[idx*3 +1], 
-                    sizeof(char), sizeof(uch), pFile);
-                fread((char*)&(*raw_img)[idx*3 +0], 
-                    sizeof(char), sizeof(uch), pFile);
+                fread((char*)&(*raw_img)[idx*3 +2], sizeof(char), sizeof(uch), pFile);
+                fread((char*)&(*raw_img)[idx*3 +1], sizeof(char), sizeof(uch), pFile);
+                fread((char*)&(*raw_img)[idx*3 +0], sizeof(char), sizeof(uch), pFile);
             } else if(*bits == 8) { // »ÒëAˆD
-                fread((char*)&(*raw_img)[idx], 
-                    sizeof(char), sizeof(uch), pFile);
+                fread((char*)&(*raw_img)[idx], sizeof(char), sizeof(uch), pFile);
             }
         }
         fseek(pFile , (long)alig , SEEK_CUR);
@@ -188,22 +165,29 @@ typedef struct Imgraw {
     uint16_t bits;
     uch* data;
 } Imgraw;
+
 void Imgraw_Read(const Imgraw* _this, const char* name) {
     const Imgraw* p = _this;
     bmpRead(name, &p->data, &p->width, &p->height, &p->bits);
 }
-void Imgraw_Writ(const Imgraw* _this, const char* name, const char* old_name) {
+void Imgraw_Writ(const Imgraw* _this, const char* name, float radio_w, float radio_h) {
     const Imgraw* p = _this;
-    bmpWrite(name, p->data, p->width, p->height, p->bits, old_name, 1.0);
+    bmpWrite(name, p->data, p->width, p->height, p->bits, radio_w, radio_h);
 }
 /*==============================================================*/
 int main(int argc, char const *argv[]) {
+    float radio_w, radio_h;
+    printf("Enter a radio of width :") ;
+    scanf("%f", &radio_w);
+    printf("Enter a radio of height :") ;
+    scanf("%f", &radio_h);
+    printf("%f :: %f\n", radio_w, radio_h);
     // ½¨˜‹
     Imgraw img = {0, 0, 0, NULL};
     // ×xˆD
-    Imgraw_Read(&img, "./input/bw2x1.bmp");
+    Imgraw_Read(&img, "./input/bw2x3.bmp");
     // Œ‘ˆD
-    Imgraw_Writ(&img, "./output/bw2x1(output).bmp", "./input/bw2x1.bmp");
+    Imgraw_Writ(&img, "./output/bw2x3(output).bmp", radio_w, radio_h);
     return 0;
 }
 /*==============================================================*/

try.c

@@ -0,0 +1,290 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <inttypes.h>
+#include <math.h>
+typedef unsigned char uch;
+
+
+// 檔案結構
+#pragma pack(2)
+struct BmpFileHeader {
+    uint16_t bfTybe;
+    uint32_t bfSize;
+    uint16_t bfReserved1;
+    uint16_t bfReserved2;
+    uint32_t bfOffBits;
+};
+struct BmpInfoHeader {
+    uint32_t biSize;
+    uint32_t biWidth;
+    uint32_t biHeight;
+    uint16_t biPlanes; // 1=defeaul, 0=custom
+    uint16_t biBitCount;
+    uint32_t biCompression;
+    uint32_t biSizeImage;
+    uint32_t biXPelsPerMeter; // 72dpi=2835, 96dpi=3780
+    uint32_t biYPelsPerMeter; // 120dpi=4724, 300dpi=11811
+    uint32_t biClrUsed;
+    uint32_t biClrImportant;
+};
+#pragma pack()
+
+//辅助计算函数
+float linear_single(float x, float x1, float x2, float f1, float f2){
+    return floor(f1 * (x2 - x) / (x2 - x1) + f2 * (x - x1) / (x2 - x1));
+}
+
+// 双线性插值函数
+// 参考 https://zh.wikipedia.org/wiki/%E5%8F%8C%E7%BA%BF%E6%80%A7%E6%8F%92%E5%80%BC
+char linear_insert(uch** old_pixels, uint32_t row, uint32_t col, uint32_t old_width, uint32_t old_height, float radio_w, float radio_h){
+    float x = row / radio_h;
+    float y = col / radio_w;
+    // 如果整数格点就直接返回
+    int x1 = floor(x);
+    int x2 = ceil(x);
+    int y1 = floor(y);
+    int y2 = ceil(y);
+    if (x2 >= old_height){x2 = x1;}
+        
+    if (y2 >= old_width){y2 = y1;}
+    if (x1 == x2 && y1 == y2){return old_pixels[x1][y1];}
+    if (x1 == x2){
+        int x = x1;
+        uint32_t idx1 = x*old_width+y;
+        uint32_t idx2 = x*old_width+y;
+        float r = linear_single(y, y1, y2, old_pixels[x][idx1 + 0], old_pixels[x][idx2 + 0]);
+        float g = linear_single(y, y1, y2, old_pixels[x][idx1 + 1], old_pixels[x][idx2 + 1]);
+        float b = linear_single(y, y1, y2, old_pixels[x][idx1 + 2], old_pixels[x][idx2 + 2]);
+        return (char)r, (char)g, (char)b;
+    }
+    if (y1 == y2){
+        int y = y1;
+        uint32_t idx = x*old_width+y;
+        float r = linear_single(x, x1, x2, old_pixels[x1][idx + 0], old_pixels[x2][idx + 0]);
+        float g = linear_single(x, x1, x2, old_pixels[x1][idx + 1], old_pixels[x2][idx + 1]);
+        float b = linear_single(x, x1, x2, old_pixels[x1][idx + 2], old_pixels[x2][idx + 2]);
+        return (char)r, (char)g, (char)b;
+    }
+    uint32_t idx1 = x*old_width+y;
+    uint32_t idx2 = x*old_width+y;
+    float fy1_r = linear_single(x, x1, x2, old_pixels[x1][idx1 + 0], old_pixels[x2][idx1 + 0]);
+    float fy1_g = linear_single(x, x1, x2, old_pixels[x1][idx1 + 1], old_pixels[x2][idx1 + 1]);
+    float fy1_b = linear_single(x, x1, x2, old_pixels[x1][idx1 + 2], old_pixels[x2][idx1 + 2]);
+    float fy2_r = linear_single(x, x1, x2, old_pixels[x1][idx2 + 0], old_pixels[x2][idx2 + 0]);
+    float fy2_g = linear_single(x, x1, x2, old_pixels[x1][idx2 + 1], old_pixels[x2][idx2 + 1]);
+    float fy2_b = linear_single(x, x1, x2, old_pixels[x1][idx2 + 2], old_pixels[x2][idx2 + 2]);
+    float r = linear_single(y, y1, y2, fy1_r, fy2_r);
+    float g = linear_single(y, y1, y2, fy1_g, fy2_g);
+    float b = linear_single(y, y1, y2, fy1_b, fy2_b);
+    return (char)r, (char)g, (char)b;
+}
+
+void bmpWrite(const char* name, const uch* raw_img, uint32_t width, uint32_t height, uint32_t bits, float radio_w, float radio_h){
+    if(!(name && raw_img)){
+        perror("Error bmpWrite.");
+        return;
+    }
+    // 檔案資訊
+    struct BmpFileHeader file_h = {
+        .bfTybe=0x4d42,
+        .bfReserved1=0,
+        .bfReserved2=0,
+        .bfOffBits=54,
+    };
+
+    uint32_t new_width = floor(width*radio_w);
+    uint32_t new_height = floor(height*radio_h);
+    file_h.bfSize = file_h.bfOffBits + new_width*new_height * bits/8;
+    if(bits==8) {file_h.bfSize+= 1024, file_h.bfOffBits+= 1024;}
+
+
+    // 圖片資訊
+    struct BmpInfoHeader info_h = {
+        .biSize=40,
+        .biPlanes=1,
+        .biCompression=0,
+        .biXPelsPerMeter=0,
+        .biYPelsPerMeter=0,
+        .biClrUsed=0,
+        .biClrImportant=0,
+    };
+    info_h.biWidth = new_width;
+    info_h.biHeight = new_height;
+    info_h.biBitCount = bits;// 多少位的圖
+    info_h.biSizeImage = new_width*new_height * bits/8;
+    if(bits == 8) {info_h.biClrUsed=256;}
+    // 寫入檔頭
+    FILE *pFile = NULL;
+    // pFile = fopen(name,"wb+");
+    fopen_s(&pFile, name,"wb+");
+    if(!pFile) {
+        perror("Error opening file.");
+        return;
+    }
+    fwrite((char*)&file_h, sizeof(char), sizeof(file_h), pFile);
+    fwrite((char*)&info_h, sizeof(char), sizeof(info_h), pFile);
+    // 寫調色盤
+    if(bits == 8) {
+        for(unsigned i = 0; i < 256; ++i) {
+            uch c = i;
+            fwrite((char*)&c, sizeof(char), sizeof(uch), pFile);
+            fwrite((char*)&c, sizeof(char), sizeof(uch), pFile);
+            fwrite((char*)&c, sizeof(char), sizeof(uch), pFile);
+            fwrite("", sizeof(char), sizeof(uch), pFile);
+        }
+    }
+
+    // char newpixels[new_width*new_height];
+    unsigned char **newpixels=(unsigned char**)malloc(new_width*new_height*3);// 沒用到
+	
+    // 寫入圖片資訊
+    size_t alig = ((new_width*bits/8)*3) % 4;
+    // for(int j = new_height-1; j >= 0; --j) {
+    //     for(unsigned i = 0; i < new_width; ++i) {
+    //         uint32_t idx = j*new_width +i;
+    //         if(bits == 24) { // RGB圖片
+    //             fwrite((char*)&raw_img[idx*3 +2], sizeof(char), sizeof(uch), pFile);
+    //             fwrite((char*)&raw_img[idx*3 +1], sizeof(char), sizeof(uch), pFile);
+    //             fwrite((char*)&raw_img[idx*3 +0], sizeof(char), sizeof(uch), pFile);
+    //         } else if(bits == 8) { // 灰階圖
+    //             fwrite((char*)&raw_img[idx], sizeof(char), sizeof(uch), pFile);
+    //         }
+    //     }
+
+
+    for(int j = new_height-1; j >= 0; --j) {
+        for(unsigned i = 0; i < new_width; ++i) {
+            uint32_t idx = j*new_width +i;
+            if(bits == 24) { // RGB圖片
+                char* r, g, b = linear_insert(&raw_img, j, i, width, height, radio_w, radio_h);
+                fwrite(b, sizeof(char), sizeof(uch), pFile);
+                fwrite(g, sizeof(char), sizeof(uch), pFile);
+                fwrite(r, sizeof(char), sizeof(uch), pFile);
+            } else if(bits == 8) { // 灰階圖
+                fwrite((char*)&raw_img[idx], sizeof(char), sizeof(uch), pFile);
+            }
+        }
+        //# 计算新像素
+        // 對齊4byte
+        for(size_t i = 0; i < alig; ++i) {
+            fwrite("", sizeof(char), sizeof(uch), pFile);
+        }
+    }
+    fclose(pFile);
+
+    free(newpixels); //記得釋放空間
+}
+void bmpRead(const char* name, uch** oldpixels, uint32_t* width, uint32_t* height, uint16_t* bits)
+{
+    if(!(name && oldpixels && width && height && bits)) {
+        perror("Error bmpRead.");
+        return;
+    }
+    // 檔案資訊
+    struct BmpFileHeader file_h;
+    // 圖片資訊
+    struct BmpInfoHeader info_h;
+    // 讀取檔頭
+    FILE *pFile = NULL;
+    // pFile = fopen(name, "rb+");
+    fopen_s(&pFile, name, "rb+");
+    if(!pFile) {
+        perror("Error opening file.");
+        return;
+    }
+    fread((char*)&file_h, sizeof(char), sizeof(file_h), pFile);
+    fread((char*)&info_h, sizeof(char), sizeof(info_h), pFile);
+    // 讀取長寬
+    *width = info_h.biWidth;
+    *height = info_h.biHeight;
+    *bits = info_h.biBitCount;
+    unsigned char **oldpixels=(unsigned char**)malloc((*width)*(*height)*3);
+
+    // size_t ImgSize = ((size_t)*width) * ((size_t)*height) * 3;
+    // *raw_img = (uch*)calloc(ImgSize, sizeof(uch));
+    // 讀取讀片資訊轉RAW檔資訊
+    fseek(pFile, file_h.bfOffBits, SEEK_SET);
+    size_t alig = ((info_h.biWidth*info_h.biBitCount/8)*3) % 4;
+    for(int j = *height-1; j >= 0; --j) {
+        for(unsigned i = 0; i < *width; ++i) {
+            uint32_t idx = j*(*width)+i;
+            if(*bits == 24) { // RGB圖片
+                fread((char*)&(*oldpixels)[idx*3 +2], sizeof(char), sizeof(uch), pFile);
+                fread((char*)&(*oldpixels)[idx*3 +1], sizeof(char), sizeof(uch), pFile);
+                fread((char*)&(*oldpixels)[idx*3 +0], sizeof(char), sizeof(uch), pFile);
+            } else if(*bits == 8) { // 灰階圖
+                fread((char*)&(*oldpixels)[idx], sizeof(char), sizeof(uch), pFile);
+            }
+        }
+        fseek(pFile , (long)alig , SEEK_CUR);
+    }
+    fclose(pFile);
+
+
+//---------------------------------------------------------------------------
+    // size_t ImgSize = ((size_t)*width) * ((size_t)*height) * 3;
+    // *raw_img = (uch*)calloc(ImgSize, sizeof(uch));
+    // // 讀取讀片資訊轉RAW檔資訊
+    // fseek(pFile, file_h.bfOffBits, SEEK_SET);
+    // size_t alig = ((info_h.biWidth*info_h.biBitCount/8)*3) % 4;
+    // for(int j = *height-1; j >= 0; --j) {
+    //     for(unsigned i = 0; i < *width; ++i) {
+    //         uint32_t idx = j*(*width)+i;
+    //         if(*bits == 24) { // RGB圖片
+    //             fread((char*)&(*raw_img)[idx*3 +2], sizeof(char), sizeof(uch), pFile);
+    //             fread((char*)&(*raw_img)[idx*3 +1], sizeof(char), sizeof(uch), pFile);
+    //             fread((char*)&(*raw_img)[idx*3 +0], sizeof(char), sizeof(uch), pFile);
+    //         } else if(*bits == 8) { // 灰階圖
+    //             fread((char*)&(*raw_img)[idx], sizeof(char), sizeof(uch), pFile);
+    //         }
+    //     }
+    //     fseek(pFile , (long)alig , SEEK_CUR);
+    // }
+    // fclose(pFile);
+//----------------------------------------------------------------------------
+
+    // for(int j = *height-1; j >= 0; --j) {
+    //     for(unsigned i = 0; i < *width; ++i) {
+    //         uint32_t idx = j*(*width)+i;
+    //         for(int k = 0; k < 3; k++){
+    //             printf((char*)&(*raw_img)[idx*3 + k]);
+    //             printf("\t");
+    //         }
+    //         printf("\t done \t");
+    //     }
+    //     printf("\n");
+    // }
+}
+
+// 圖像結構
+typedef struct Imgraw {
+    uint32_t width, height;
+    uint16_t bits;
+    uch* data;
+} Imgraw;
+
+void Imgraw_Read(const Imgraw* _this, const char* name) {
+    const Imgraw* p = _this;
+    bmpRead(name, &p->data, &p->width, &p->height, &p->bits);
+}
+void Imgraw_Writ(const Imgraw* _this, const char* name, float radio_w, float radio_h) {
+    const Imgraw* p = _this;
+    bmpWrite(name, p->data, p->width, p->height, p->bits, radio_w, radio_h);
+}
+/*==============================================================*/
+int main(int argc, char const *argv[]) {
+    float radio_w, radio_h;
+    printf("Enter a radio of width :") ;
+    scanf("%f", &radio_w);
+    printf("Enter a radio of height :") ;
+    scanf("%f", &radio_h);
+    printf("%f :: %f\n", radio_w, radio_h);
+    // 建構
+    Imgraw img = {0, 0, 0, NULL};
+    // 讀圖
+    Imgraw_Read(&img, "./input/bw2x1.bmp");
+    // 寫圖
+    Imgraw_Writ(&img, "./output/bw2x1(output).bmp", radio_w, radio_h);
+    return 0;
+}
+/*==============================================================*/