C ++：旋转图像BMP [英] C++: rotate image BMP
本文介绍了C ++：旋转图像BMP的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我对BMP图像的这种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......但没有人能让我理解这里发生的事情和我该如何解决这个问题。
I have some serious problems with this stupid rotation function of a BMP image... I've already post the same question now 2 days ago, I know... But no one could make me to understand what's happening here and how can I solve this issue.
编辑：该图像将以90度多重旋转。
that image will be rotated just with 90 degrees multipler.
在这一刻，我正在尝试以180度旋转此图像
In this moment I'm trying to rotate this image with an 180 degree
这是我的结果，直到这一刻
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;
}
所以请大家好，求求你们...你们其中一个能帮助我吗？解决这个愚蠢的问题谁几乎没有杀我2天：/
So please guys, I beg you... Could one of you help me to solve this stupid problem who kill me 2 days for almost nothing :/
谢谢
推荐答案
EDIT_2：
检查完整代码：
EDIT_2:
Check full code:
#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：
如果只有 0,90,180,270 旋转度数，这里是旋转 180 度的示例，如果你想用<$来修改它c $ c> 0,90,270 （当 rotate_degree = 90或270 时，图像宽度和高度更改）：
EDIT_1:
If only 0,90,180,270 degrees to rotate, here is the example of rotate 180 degrees, modify it if you want to do it with 0,90,270(image width and height change when rotate_degree = 90 or 270):
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;
}
另一个解决方案：我们可以使用 CImage 来自 atlimage.h ：
Another solution : We can use CImage from 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：
Result:
这篇关于C ++：旋转图像BMP的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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