Класс для конвертации PNG

[Digger Man]

Была надобность написать такой класс, для того, что бы можно было сразу все файлы в директории конвертировать в ICO, BMP.

#pragma pack(push, 2)
struct BitmapFileHeader {
    uint16_t type;
    uint32_t size;
    uint16_t reserved1;
    uint16_t reserved2;
    uint32_t offset;
};

struct BitmapInfoHeader {
    uint32_t size;
    int32_t width;
    int32_t height;
    uint16_t planes;
    uint16_t bitCount;
    uint32_t compression;
    uint32_t sizeImage;
    int32_t xPelsPerMeter;
    int32_t yPelsPerMeter;
    uint32_t clrUsed;
    uint32_t clrImportant;
};

struct IconHeader {
    uint16_t reserved;
    uint16_t type;
    uint16_t count;
};

struct IconDirectoryEntry {
    uint8_t width;
    uint8_t height;
    uint8_t colorCount;
    uint8_t reserved;
    uint16_t planes;
    uint16_t bitCount;
    uint32_t sizeInBytes;
    uint32_t offset;
};

static const char ppm_header[] = "P6\n32 32\n255\n"; // P6 - формаит PPM, 32 32 - размер, 255 цветовой компонент от 0 до 255
#pragma pack(pop)

class ImageConverter {
public:
    void ConvertPNGtoBMP(const std::string& inputFileName, const std::string& outputFileName) {
        std::ifstream inputFile(inputFileName, std::ios::binary);
        if (!inputFile) {
            std::cerr << "Error reading input file." << std::endl;
            return;
        }

        std::ofstream outputFile(outputFileName, std::ios::binary);
        if (!outputFile) {
            std::cerr << "Error writing to output file." << std::endl;
            return;
        }

        BitmapFileHeader fileHeader;
        fileHeader.type = 0x4D42;
        fileHeader.reserved1 = 0;
        fileHeader.reserved2 = 0;

        BitmapInfoHeader infoHeader;
        infoHeader.size = sizeof(BitmapInfoHeader);
        infoHeader.width = 32;
        infoHeader.height = 32;
        infoHeader.planes = 1;
        infoHeader.bitCount = 24;
        infoHeader.compression = 0;
        infoHeader.sizeImage = 0;
        infoHeader.xPelsPerMeter = 0;
        infoHeader.yPelsPerMeter = 0;
        infoHeader.clrUsed = 0;
        infoHeader.clrImportant = 0;

        outputFile.write(reinterpret_cast<const char*>(&fileHeader), sizeof(fileHeader));
        outputFile.write(reinterpret_cast<const char*>(&infoHeader), sizeof(infoHeader));


        std::vector<uint8_t> imageData(32 * 32 * 3, 0);

        outputFile.write(reinterpret_cast<const char*>(imageData.data()), imageData.size());
    }
    void ConvertPNGtoPPM(const std::string& inputFileName, const std::string& outputFileName) {
        std::ifstream inputFile(inputFileName, std::ios::binary);
        if (!inputFile) {
            std::cerr << "Error reading input file." << std::endl;
            return;
        }

        std::vector<uint8_t> imageData((std::istreambuf_iterator<char>(inputFile)), std::istreambuf_iterator<char>());


        std::ofstream outputFile(outputFileName, std::ios::binary);
        if (!outputFile) {
            std::cerr << "Error writing to output file." << std::endl;
            return;
        }

        outputFile.write(ppm_header, sizeof(ppm_header) - 1);
        outputFile.write(reinterpret_cast<const char*>(imageData.data()), imageData.size());

        if (!outputFile) {
            std::cerr << "Error writing to output file." << std::endl;
            return;
        }
    }
    void ConvertPNGtoICO(const std::string& inputFileName, const std::string& outputFileName) {
        std::ifstream inputFile(inputFileName, std::ios::binary);
        if (!inputFile) {
            std::cerr << "Error reading input file." << std::endl;
            return;
        }

        std::vector<uint8_t> imageData((std::istreambuf_iterator<char>(inputFile)), std::istreambuf_iterator<char>());

        IconHeader iconHeader = { 0, 1, 1 };
        IconDirectoryEntry directoryEntry = { 32, 32, 0, 0, 1, 32, static_cast<uint32_t>(imageData.size()), 22 };

        std::ofstream outputFile(outputFileName, std::ios::binary);
        if (!outputFile) {
            std::cerr << "Error writing to output file." << std::endl;
            return;
        }


        outputFile.write(reinterpret_cast<const char*>(&iconHeader), sizeof(iconHeader));
        outputFile.write(reinterpret_cast<const char*>(&directoryEntry), sizeof(directoryEntry));
        outputFile.write(reinterpret_cast<const char*>(imageData.data()), imageData.size());

        if (!outputFile) {
            std::cerr << "Error writing to output file." << std::endl;
            return;
        }
    }
};

Структуры спизжены с Polychaos если что

пример использования