C++实现图片jpg格式变成16位565bmp格式

// consoleapplication1.cpp : 此文件包含 "main" 函数。程序执行将在此处开始并结束。
//

#include <iostream>
#include<string>
#include <atlimage.h>

bool convertjpgto16bitbmp565(const char* input_path, const char* output_path) {
    cimage srcimage, dstimage;

    // 1. 加载源图像
    srcimage.load(input_path);

    int width = srcimage.getwidth();
    int height = srcimage.getheight();
    int srcbpp = srcimage.getbpp();
    int srcpitch = srcimage.getpitch();
    byte* srcbits = static_cast<byte*>(srcimage.getbits());

    // 2. 创建目标图像（负高度表示自上而下存储）
    dword masks[] = { 0xf800, 0x07e0, 0x001f };
    dstimage.createex(width, height, 16, bi_bitfields, masks);

    // 3. 获取目标图像参数（实际步长由api返回）
    int dstpitch = dstimage.getpitch();
    byte* dstbits = static_cast<byte*>(dstimage.getbits());
    // 5. 处理像素数据（无需反转行顺序）
    for (int y = 0; y < height; ++y) {
        byte* srcrow = srcbits + y * srcpitch;
        byte* dstrow = dstbits + y * dstpitch;

        for (int x = 0; x < width; ++x) {
            byte r, g, b;

            // 解析源像素颜色
            if (srcbpp == 24) { // 24位bgr
                byte* p = srcrow + x * 3;
                b = p[0];
                g = p[1];
                r = p[2];
            }
            else if (srcbpp == 32) { // 32位bgrx
                byte* p = srcrow + x * 4;
                b = p[0];
                g = p[1];
                r = p[2];
            }
            else {
                return false;
            }

            // 转换为rgb565
            word rgb565 = ((r >> 3) << 11) | ((g >> 2) << 5) | (b >> 3);
            // 安全写入目标像素
            dstrow[x * 2] = static_cast<byte>(rgb565 & 0xff);       // 低位字节
            dstrow[x * 2 + 1] = static_cast<byte>((rgb565 >> 8)); // 高位字节
        }
    }
    dstimage.save(output_path, gdiplus::imageformatbmp);
    return true;
}
int main()
{
    if (__argc < 2)
        return 0;
    for (int i = 1; i < __argc; i++)
    {
        std::string h = __argv[i];
        if (strcmp(h.substr(h.length() - 3).c_str(), "jpg"))
            continue;
        h=h.substr(0, h.length() - 3);
        h += "bmp";
        printf(h.c_str());
        convertjpgto16bitbmp565(__argv[i], h.c_str());
    }
    return 0;
}

#include <iostream>
#include<string>
#include <atlimage.h>

bool convertjpgto16bitbmp565(const char* input_path, const char* output_path) {
    cimage srcimage, dstimage;

    // 1. 加载源图像
    srcimage.load(input_path);

    int width = srcimage.getwidth();
    int height = srcimage.getheight();
    int srcbpp = srcimage.getbpp();
    int srcpitch = srcimage.getpitch();
    byte* srcbits = static_cast<byte*>(srcimage.getbits());

    // 2. 创建目标图像（负高度表示自上而下存储）
    dword masks[] = { 0xf800, 0x07e0, 0x001f };
    dstimage.createex(width, height, 16, bi_bitfields, masks);

    // 3. 获取目标图像参数（实际步长由api返回）
    int dstpitch = dstimage.getpitch();
    byte* dstbits = static_cast<byte*>(dstimage.getbits());
    // 5. 处理像素数据（无需反转行顺序）
    for (int y = 0; y < height; ++y) {
        byte* srcrow = srcbits + y * srcpitch;
        byte* dstrow = dstbits + y * dstpitch;

        for (int x = 0; x < width; ++x) {
            byte r, g, b;

            // 解析源像素颜色
            if (srcbpp == 24) { // 24位bgr
                byte* p = srcrow + x * 3;
                b = p[0];
                g = p[1];
                r = p[2];
            }
            else if (srcbpp == 32) { // 32位bgrx
                byte* p = srcrow + x * 4;
                b = p[0];
                g = p[1];
                r = p[2];
            }
            else {
                return false;
            }

            // 转换为rgb565
            word rgb565 = ((r >> 3) << 11) | ((g >> 2) << 5) | (b >> 3);
            // 安全写入目标像素
            dstrow[x * 2] = static_cast<byte>((rgb565 >> 8));      // 低位字节
            dstrow[x * 2 + 1] = static_cast<byte>(rgb565 & 0xff); // 高位字节
        }
    }
    dstimage.save(output_path, gdiplus::imageformatbmp);
    return true;
}
int main()
{
    if (__argc < 2)
        return 0;
    for (int i = 1; i < __argc; i++)
    {
        std::string h = __argv[i];
        if (strcmp(h.substr(h.length() - 3).c_str(), "jpg"))
            continue;
        h=h.substr(0, h.length() - 3);
        h += "bmp";
        printf(h.c_str());
        convertjpgto16bitbmp565(__argv[i], h.c_str());
    }
    return 0;
}

#include <opencv2/opencv.hpp>
#include <iostream>
 
int main() {
    // 输入文件路径和输出文件路径
    std::string inputimagepath, outputimagepath;
    
    std::cout << "enter the input image file path: ";
    std::cin >> inputimagepath;
    
    std::cout << "enter the output image file path (e.g., output.png, output.jpg): ";
    std::cin >> outputimagepath;
 
    // 读取图片
    cv::mat image = cv::imread(inputimagepath, cv::imread_unchanged);
 
    // 检查图片是否成功加载
    if (image.empty()) {
        std::cerr << "error: could not open or find the image!" << std::endl;
        return -1;
    }
 
    // 保存图片到新格式
    bool success = cv::imwrite(outputimagepath, image);
 
    if (success) {
        std::cout << "image successfully converted and saved to " << outputimagepath << std::endl;
    } else {
        std::cerr << "error: could not save the image!" << std::endl;
    }
 
    return 0;
}