C ++：旋转图像BMP

Question

我对BMP图像的这个愚蠢的旋转功能有一些严重的问题...我已经在2天前发布了同样的问题，我知道......但没有人能让我明白什么＆＃ 39; s发生在这里，我该如何解决这个问题。

编辑：该图片将以90度多重旋转。

在这一刻我试图以180度旋转此图像

此时此刻我的结果

这是我的代码：

#include <algorithm>
#include <fstream>
#include <math.h>
#include <vector>
#include <iostream>

using namespace std;

double PI = 3.141592653589793238462643383279;
struct BMP {
    int width;
    int height;
    unsigned char header[54];
    unsigned char *pixels;
    int row_padded;
    int size_padded;
};

void writeBMP(string filename, BMP image) {
    string fileName = "Output Files\\" + filename;
    FILE *out = fopen(fileName.c_str(), "wb");
    fwrite(image.header, sizeof(unsigned char), 54, out);

    unsigned char tmp;
    for (int i = 0; i < image.height; i++) {
        for (int j = 0; j < image.width * 3; j += 3) {
            //Convert(B, G, R) to(R, G, B)
            tmp = image.pixels[j];
            image.pixels[j] = image.pixels[j + 2];
            image.pixels[j + 2] = tmp;
        }
    }
    fwrite(image.pixels, sizeof(unsigned char), image.size_padded, out);
    fclose(out);
}

BMP readBMP(string filename) {
    BMP image;
    string fileName = "Input Files\\" + filename;
    FILE *in = fopen(fileName.c_str(), "rb");

    if (in == NULL)
        throw "Argument Exception";

    fread(image.header, sizeof(unsigned char), 54, in); // read the 54-byte header

    // extract image height and width from header
    image.width = *(int *) &image.header[18];
    image.height = *(int *) &image.header[22];

    image.row_padded = (image.width * 3 + 3) & (~3);     // ok size of a single row rounded up to multiple of 4
    image.size_padded = image.row_padded * image.height;  // padded full size
    image.pixels = new unsigned char[image.size_padded];  // yeah !

    if (fread(image.pixels, sizeof(unsigned char), image.size_padded, in) == image.size_padded) {
        unsigned char tmp;
        for (int i = 0; i < image.height; i++) {
            for (int j = 0; j < image.width * 3; j += 3) {
                // Convert (B, G, R) to (R, G, B)
                tmp = image.pixels[j];
                image.pixels[j] = image.pixels[j + 2];
                image.pixels[j + 2] = tmp;
            }
        }
    } else {
        cout << "Error: all bytes couldn't be read" << endl;
    }

    fclose(in);
    return image;
}

BMP rotate(BMP image, double degree) {
    BMP newImage = image;
    unsigned char *pixels = new unsigned char[image.size_padded];

    double radians = (degree * PI) / 180;
    int sinf = (int) sin(radians);
    int cosf = (int) cos(radians);

    double x0 = 0.5 * (image.width - 1);     // point to rotate about
    double y0 = 0.5 * (image.height - 1);     // center of image

    // rotation
    for (int x = 0; x < image.height; x++) {
        for (int y = 0; y < image.width * 3; y += 3) {
            long double a = x - x0;
            long double b = y - y0;
            int xx = (int) (+a * cosf - b * sinf + x0);
            int yy = (int) (+a * sinf + b * cosf + y0);

            if (xx >= 0 && xx < image.width && yy >= 0 && yy < image.height) {
                pixels[(y * image.width + x) * 3 + 0] = image.pixels[(yy * image.width + xx) * 3 + 0];
                pixels[(y * image.width + x) * 3 + 1] = image.pixels[(yy * image.width + xx) * 3 + 1];
                pixels[(y * image.width + x) * 3 + 2] = image.pixels[(yy * image.width + xx) * 3 + 2];
            }
        }
    }
    newImage.pixels = pixels;
    return newImage;
}

int main() {
    BMP image = readBMP("Image.bmp");
    image = rotate(image, 180);
    writeBMP("Output.bmp", image);
    return 0;
}

所以请伙计们，求求你们......你们中有谁能帮助我解决这个愚蠢的问题，他几乎什么都没杀我2天：/

谢谢

Answer 1

EDIT_2：

检查完整代码：

#include <algorithm>
#include <fstream>
#include <math.h>
#include <vector>
#include <string>
#include <iostream>
#include <chrono>
//#include "operation_parser.h"

using namespace std;
using namespace std::chrono;

double PI = 3.141592653589793238462643383279;
struct BMP {
    int width;
    int height;
    unsigned char header[54];
    unsigned char *pixels;
    int size;
    int row_padded;
    long long int size_padded;
};

void writeBMP(string filename, BMP image) {
    string fileName = filename;
    FILE *out = fopen(fileName.c_str(), "wb");
    fwrite(image.header, sizeof(unsigned char), 54, out);

    unsigned char tmp;
    for (int i = 0; i < image.height; i++) {
        for (int j = 0; j < image.width * 3; j += 3) {
            //Convert(B, G, R) to(R, G, B)
            tmp = image.pixels[j];
            image.pixels[j] = image.pixels[j + 2];
            image.pixels[j + 2] = tmp;
        }
    }
    fwrite(image.pixels, sizeof(unsigned char), image.size_padded, out);
    fclose(out);
}

BMP readBMP(string filename) {
    BMP image;
    string fileName = filename;
    FILE *in = fopen(fileName.c_str(), "rb");

    if (in == NULL)
        throw "Argument Exception";

    fread(image.header, sizeof(unsigned char), 54, in); // read the 54-byte header

    // extract image height and width from header
    image.width = *(int *) &image.header[18];
    image.height = *(int *) &image.header[22];

    image.row_padded = (image.width * 3 + 3) & (~3);     // ok size of a single row rounded up to multiple of 4
    image.size_padded = image.row_padded * image.height;  // padded full size
    image.pixels = new unsigned char[image.size_padded];  // yeah !

    if (fread(image.pixels, sizeof(unsigned char), image.size_padded, in) == image.size_padded) {
        unsigned char tmp;
        for (int i = 0; i < image.height; i++) {
            for (int j = 0; j < image.width * 3; j += 3) {
                // Convert (B, G, R) to (R, G, B)
                tmp = image.pixels[j];
                image.pixels[j] = image.pixels[j + 2];
                image.pixels[j + 2] = tmp;
            }
        }
    } else {
        cout << "Error: all bytes couldn't be read" << endl;
    }

    fclose(in);
    return image;
}

BMP rotate180Degree(BMP image, double degree) {
    _ASSERTE(degree == 180.0);

    BMP newImage = image;
    unsigned char *pixels = new unsigned char[image.size_padded];

    int H = image.height, W = image.width;
    for (int x = 0; x < H; x++) {
        for (int y = 0; y < W;y ++) {
            pixels[(x * W + y) * 3 + 0] = image.pixels[((H - 1 - x) * W + (W - 1 - y)) * 3 + 0];
            pixels[(x * W + y) * 3 + 1] = image.pixels[((H - 1 - x) * W + (W - 1 - y)) * 3 + 1];
            pixels[(x * W + y) * 3 + 2] = image.pixels[((H - 1 - x) * W + (W - 1 - y)) * 3 + 2];
        }
    }

    newImage.pixels = pixels;
    return newImage;
}

int main() {
    BMP image = readBMP("test.bmp");
    image = rotate180Degree(image, 180);
    writeBMP("Output.bmp", image);
    return 0;
}

EDIT_1：

如果仅旋转0,90,180,270度，此处是旋转 180 度的示例，如果要使用0,90,270（图像宽度和高度<当rotate_degree = 90 or 270）时强>更改：

BMP rotate180Degree(BMP image, double degree) {
    _ASSERTE(degree == 180.0);

    BMP newImage = image;
    unsigned char *pixels = new unsigned char[image.size_padded];

    int H = image.height, W = image.width;
    for (int x = 0; x < H; x++) {
        for (int y = 0; y < W;y ++) {
            pixels[(x * W + y) * 3 + 0] = image.pixels[((H - 1 - x) * W + (W - 1 - y)) * 3 + 0];
            pixels[(x * W + y) * 3 + 1] = image.pixels[((H - 1 - x) * W + (W - 1 - y)) * 3 + 1];
            pixels[(x * W + y) * 3 + 2] = image.pixels[((H - 1 - x) * W + (W - 1 - y)) * 3 + 2];
        }
    }

    newImage.pixels = pixels;
    return newImage;
}

另一种解决方案：我们可以使用CImage中的atlimage.h：

std::shared_ptr<CImage> OriginalImg = std::make_shared<CImage>();
OriginalImg->Load("test.png");

int W = OriginalImg->GetWidth(), H = OriginalImg->GetHeight();

std::shared_ptr<CImage> RotatedImg = std::make_shared<CImage>();
RotatedImg->Create(W, H, OriginalImg->GetBPP());

for (unsigned int x = 0; x < W; ++x)
{
    for (unsigned int y = 0; y < H; ++y)
    {
        RotatedImg->SetPixel(x, y, OriginalImg->GetPixel(W - x - 1, H - y - 1));
    }
}

RotatedImg->Save("rotatedImage.png");

结果：