Qt5--BMP图片由RGB888转RGB565

桃扇骨 2022-12-20 02:43 245阅读 0赞

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI4ODc3MTI1_size_16_color_FFFFFF_t_70_pic_center]

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI4ODc3MTI1_size_16_color_FFFFFF_t_70_pic_center 1]mainwindow.h

#ifndef MAINWINDOW_H
    #define MAINWINDOW_H
    
    #include <QMainWindow>
    #include <QFileDialog>
    #include <QFile>
    #include <QDebug>
    
    QT_BEGIN_NAMESPACE
    namespace Ui {  class MainWindow; }
    QT_END_NAMESPACE
    
    #define ORIENT_DEFAULT 0
    #define ORIENT_FROM_TOP 1
    #define ORIENT_FROM_BOTTOM 2
    
    struct BITMAPFILEHEADER
    { 
      unsigned short    bfType; // "BM" = 0x4d42
      unsigned int      bfSize; // file size
      unsigned short    bfReserved1; // reserved = 0
      unsigned short    bfReserved2; // reserved = 0
      unsigned int      bfOffBits; // image offset
    };
    
    struct BITMAPINFOHEADER
    { 
      unsigned int      biSize; // size of struct
      unsigned int      biWidth; // width
      signed int        biHeight; // height
      unsigned short    biPlanes; // in bmp = 1
      unsigned short    biBitCount; // bpp
      unsigned int      biCompression; // 3 with pallete, 0 without pallete
      unsigned int      biSizeImage; // raw size
      unsigned int      biXPelsPerMeter; // px per m (0xec4)
      unsigned int      biYPelsPerMeter; // px per m (0xec4)
      unsigned int      biClrUsed; // 0
      unsigned int      biClrImportant; // 0
    };
    
    class MainWindow : public QMainWindow
    { 
        Q_OBJECT
    
    public:
        MainWindow(QWidget *parent = nullptr);
        ~MainWindow();
    
    private slots:
        void on_selectBtn_clicked();
    
        void on_converBtn_clicked();
    
    private:
        void initStruct(char* data, uint count);
    
        ushort checkBMPbpp(QString pathImage);
    
        uint getBMPorient(QString path);
    
        void bmp16Turn(QString srcPath, QString destPath);
    
        void convert24to16(QString srcPath, QString destPath, int orient);
    private:
        Ui::MainWindow *ui;
        QStringList     gFileDir;
    };
    #endif // MAINWINDOW_H

mainwindow.cpp

#include "mainwindow.h"
    #include "ui_mainwindow.h"
    
    MainWindow::MainWindow(QWidget *parent)
        : QMainWindow(parent)
        , ui(new Ui::MainWindow)
    { 
        ui->setupUi(this);
    }
    
    MainWindow::~MainWindow()
    { 
        delete ui;
    }
    
    
    void MainWindow::on_selectBtn_clicked()
    { 
        QFileDialog *fileDialog = new QFileDialog(this);
    
        fileDialog->setWindowTitle("choice file");
    
        fileDialog->setDirectory(".");
    
        //fileDialog->setNameFilter(tr("mp3(*)")); // 文件类型过滤
    
        fileDialog->setFileMode(QFileDialog::ExistingFiles);
    
        fileDialog->setViewMode(QFileDialog::Detail);
    
        QStringList fileNames;
        if(fileDialog->exec())
        { 
            fileNames = fileDialog->selectedFiles();
        }
        ui->textEdit->append(QString(fileNames.join("/")));
        gFileDir = fileNames;
    
        QPixmap pixmap(QString(gFileDir.join("/")));
        ui->originlabel->setPixmap(pixmap);
        ui->originlabel->setScaledContents(true);
        ui->originlabel->show();
    }
    
    void MainWindow::on_converBtn_clicked()
    { 
        uint16_t bpp = checkBMPbpp(QString(gFileDir.join("/")));
    
        QString tempPath = QFileDialog::getSaveFileName(this,
                                                        "Save 16-bit *.bmp image:",
                                                        "",
                                                        "*.bmp");
        if (tempPath.isEmpty() == true)
        { 
            return;
        }
        if (tempPath.right(4).compare(".bmp", Qt::CaseInsensitive) != 0)
            tempPath.append(".bmp");
        if (bpp == 24)
        { 
            qDebug() << "bpp = 24";
            convert24to16(QString(gFileDir.join("/")), tempPath, ORIENT_DEFAULT);
        }
        else if (bpp == 16)
        { 
            qDebug() << "bpp = 16";
            bmp16Turn(QString(gFileDir.join("/")), tempPath);
        }
        else if(bpp == 32)
        { 
            qDebug() << "bpp = 32";
        }
    
    // QPixmap pixmap(tempPath);
    // ui->afterlabel->setPixmap(pixmap);
    // ui->afterlabel->setScaledContents(true);
    // ui->afterlabel->show();
    
        QImage image;
        image.load(tempPath);
        ui->afterlabel->setScaledContents(true);
        ui->afterlabel->setPixmap(QPixmap::fromImage(image));
    }
    
    
    //=============================================================================
    void MainWindow::initStruct(char* data, uint count)
    { 
        while (count !=0)
        { 
            count--;
            data[count] = 0;
        }
    }
    //==============================================================================
    ushort MainWindow::checkBMPbpp(QString pathImage)
    { 
        // check for "BM" and return bpp
        QFile readf(pathImage);
        readf.open(QIODevice::ReadOnly);
        QDataStream streamIn(&readf);
        streamIn.setByteOrder(QDataStream::LittleEndian);
        ushort imageType;
        streamIn >> imageType;
        if (imageType != 0x4D42)
        { 
            readf.close();
            return 0;
        }
        readf.seek(28);
        ushort bpp;
        streamIn >> bpp;
        readf.close();
        return bpp;
    }
    //==============================================================================
    uint MainWindow::getBMPorient(QString path)
    { 
        QFile image(path);
        image.open(QIODevice::ReadOnly);
        QDataStream stream(&image);
        stream.setByteOrder(QDataStream::LittleEndian);
    
        int height;
    
        image.seek(22);
        stream >> height;
        image.close();
    
        if (height < 0) return ORIENT_FROM_TOP;
        else return ORIENT_FROM_BOTTOM;
    }
    //==============================================================================
    void MainWindow::bmp16Turn(QString srcPath, QString destPath)
    { 
        QFile readf(srcPath);
        QFile writef(destPath);
        readf.open(QIODevice::ReadOnly);
        writef.open(QIODevice::WriteOnly);
        QDataStream streamIn(&readf);
        streamIn.setByteOrder(QDataStream::LittleEndian);
        QDataStream streamOut(&writef);
        streamOut.setByteOrder(QDataStream::LittleEndian);
    
        BITMAPFILEHEADER imageSrc;
        initStruct((char*)&imageSrc, 14);
        // make bmp header for src 16
        streamIn >> imageSrc.bfType;
        streamIn >> imageSrc.bfSize;
        streamIn >> imageSrc.bfReserved1;
        streamIn >> imageSrc.bfReserved2;
        streamIn >> imageSrc.bfOffBits;
    
        BITMAPINFOHEADER infoSrc;
        initStruct((char*)&infoSrc, 40);
        // make bmp info for src 16
        streamIn >> infoSrc.biSize;
        streamIn >> infoSrc.biWidth;
        streamIn >> infoSrc.biHeight;
        streamIn >> infoSrc.biPlanes;
        streamIn >> infoSrc.biBitCount;
        streamIn >> infoSrc.biCompression;
        streamIn >> infoSrc.biSizeImage;
        streamIn >> infoSrc.biXPelsPerMeter;
        streamIn >> infoSrc.biYPelsPerMeter;
        streamIn >> infoSrc.biClrUsed;
        streamIn >> infoSrc.biClrImportant;
    
        // check zero-padding
        int padding = (infoSrc.biWidth * 2) % 4;
    
        BITMAPFILEHEADER imageDest;
        initStruct((char*)&imageDest, 14);
        // make bmp header for dest 16
        imageDest.bfOffBits = 0x42;
        imageDest.bfReserved2 = imageSrc.bfReserved2;
        imageDest.bfReserved1 = imageSrc.bfReserved1;
        imageDest.bfSize =
                ((infoSrc.biWidth * 2) + padding) * qAbs(infoSrc.biHeight) +
                imageDest.bfOffBits;
        imageDest.bfType = imageSrc.bfType;
    
        BITMAPINFOHEADER infoDest;
        initStruct((char*)&infoDest, 40);
        // make bmp info for dest 16
        infoDest.biSize = 0x28;
        infoDest.biWidth = infoSrc.biWidth;
        infoDest.biHeight = - infoSrc.biHeight;
        infoDest.biPlanes = infoSrc.biPlanes;
        infoDest.biBitCount = infoSrc.biBitCount;
        infoDest.biCompression = 3;
        infoDest.biSizeImage = infoSrc.biSizeImage;
        infoDest.biXPelsPerMeter = infoSrc.biXPelsPerMeter;
        infoDest.biYPelsPerMeter = infoSrc.biYPelsPerMeter;
        infoDest.biClrUsed = infoSrc.biClrUsed;
        infoDest.biClrImportant = infoSrc.biClrImportant;
    
        streamOut << imageDest.bfType;
        streamOut << imageDest.bfSize;
        streamOut << imageDest.bfReserved1;
        streamOut << imageDest.bfReserved2;
        streamOut << imageDest.bfOffBits;
    
        streamOut << infoDest.biSize;
        streamOut << infoDest.biWidth;
        streamOut << infoDest.biHeight;
        streamOut << infoDest.biPlanes;
        streamOut << infoDest.biBitCount;
        streamOut << infoDest.biCompression;
        streamOut << infoDest.biSizeImage;
        streamOut << infoDest.biXPelsPerMeter;
        streamOut << infoDest.biYPelsPerMeter;
        streamOut << infoDest.biClrUsed;
        streamOut << infoDest.biClrImportant;
        streamOut << 0xF800; // red
        streamOut << 0x7E0; // green
        streamOut << 0x1F; // blue
    
        // start turn
        int h = qAbs(infoSrc.biHeight);
        ushort pixel;
    
        readf.seek(imageSrc.bfOffBits);
        writef.seek(imageDest.bfOffBits +
                    ((infoDest.biWidth * 2) + padding) * (h - 1));
    
        while (h != 0)
        { 
            uint w = infoSrc.biWidth;
            while (w != 0)
            { 
                streamIn >> pixel;
                streamOut << pixel;
                w--;
            }
            if (padding != 0)
            { 
                streamIn >> pixel;
                streamOut << pixel;
            }
            h--;
            writef.seek(imageDest.bfOffBits +
                        ((infoDest.biWidth * 2) + padding) * (h - 1));
        }
        readf.close();
        writef.close();
    }
    //==============================================================================
    void MainWindow::convert24to16(QString srcPath, QString destPath, int orient)
    { 
        bool turn;
        QFile readf(srcPath);
        QFile writef(destPath);
    
        QFileInfo file(srcPath);
        QFileInfo file2(destPath);
    
        readf.open(QIODevice::ReadOnly);
        writef.open(QIODevice::WriteOnly);
        QDataStream streamIn(&readf);
        streamIn.setByteOrder(QDataStream::LittleEndian);
        QDataStream streamOut(&writef);
        streamOut.setByteOrder(QDataStream::LittleEndian);
    
        BITMAPFILEHEADER image24;
        initStruct((char*)&image24, 14);
        // make bmp header for 24
        streamIn >> image24.bfType;
        streamIn >> image24.bfSize;
        streamIn >> image24.bfReserved1;
        streamIn >> image24.bfReserved2;
        streamIn >> image24.bfOffBits;
    
        BITMAPINFOHEADER info24;
        initStruct((char*)&info24, 40);
        // make bmp info for 24
        streamIn >> info24.biSize;
        streamIn >> info24.biWidth;
        streamIn >> info24.biHeight;
        streamIn >> info24.biPlanes;
        streamIn >> info24.biBitCount;
        streamIn >> info24.biCompression;
        streamIn >> info24.biSizeImage;
        streamIn >> info24.biXPelsPerMeter;
        streamIn >> info24.biYPelsPerMeter;
        streamIn >> info24.biClrUsed;
        streamIn >> info24.biClrImportant;
    
        // check zero-padding
        int srcPadding = info24.biWidth % 4;
        int destPadding = (info24.biWidth * 2) % 4;
    
        BITMAPFILEHEADER image16;
        initStruct((char*)&image16, 14);
        // make bmp header for 16
        image16.bfOffBits = 0x42;
        image16.bfReserved2 = image24.bfReserved2;
        image16.bfReserved1 = image24.bfReserved1;
        image16.bfSize =
                ((info24.biWidth * 2) + destPadding) * qAbs(info24.biHeight) +
                image16.bfOffBits;
        image16.bfType = image24.bfType;
    
        BITMAPINFOHEADER info16;
        initStruct((char*)&info16, 40);
        // make bmp info for 16
        info16.biSize = 0x28;
        info16.biWidth = info24.biWidth;
    
        if ((orient == ORIENT_DEFAULT) ||
                ((orient == ORIENT_FROM_TOP) && (info24.biHeight < 0)) ||
                ((orient == ORIENT_FROM_BOTTOM) && (info24.biHeight > 0)))
        { 
            turn = false;
            info16.biHeight = info24.biHeight;
        }
        else
        { 
            turn = true;
            info16.biHeight = - info24.biHeight;
        }
    
        info16.biPlanes = 1;
        info16.biBitCount = 0x10;
        info16.biCompression = 3;
        info16.biSizeImage = image16.bfSize - image16.bfOffBits;
        info16.biXPelsPerMeter = info24.biXPelsPerMeter;
        info16.biYPelsPerMeter = info24.biYPelsPerMeter;
        info16.biClrUsed = 0;
        info16.biClrImportant = 0;
    
        streamOut << image16.bfType;
        streamOut << image16.bfSize;
        streamOut << image16.bfReserved1;
        streamOut << image16.bfReserved2;
        streamOut << image16.bfOffBits;
    
        streamOut << info16.biSize;
        streamOut << info16.biWidth;
        streamOut << info16.biHeight;
        streamOut << info16.biPlanes;
        streamOut << info16.biBitCount;
        streamOut << info16.biCompression;
        streamOut << info16.biSizeImage;
        streamOut << info16.biXPelsPerMeter;
        streamOut << info16.biYPelsPerMeter;
        streamOut << info16.biClrUsed;
        streamOut << info16.biClrImportant;
        streamOut << 0xF800; // red
        streamOut << 0x7E0; // green
        streamOut << 0x1F; // blue
    
        // start convert
        int h = qAbs(info24.biHeight);
        uchar r, g, b;
        ushort rgb16;
    
        readf.seek(image24.bfOffBits);
        if (turn)
            writef.seek(image16.bfOffBits +
                        ((info16.biWidth * 2) + destPadding) * (h - 1));
        else
            writef.seek(image16.bfOffBits);
    
        while (h != 0)
        { 
            uint w = info24.biWidth;
            while (w != 0)
            { 
                streamIn >> b;
                streamIn >> g;
                streamIn >> r;
                r = r >> 3;
                g = g >> 2;
                b = b >> 3;
                rgb16 = (r << 11) + (g << 5) + b;
                streamOut << rgb16;
                w--;
            }
            if (srcPadding != 0)
            { 
                uchar trash;
                for (int i = 0; i < srcPadding; i++) // read unneeded bytes to trash
                { 
                    streamIn >> trash;
                }
            }
            if (destPadding != 0)
            { 
                uchar p = 0;
                for (int i = 0; i < destPadding; i++)
                { 
                    streamOut << p;
                }
            }
            h--;
            if (turn)
                writef.seek(image16.bfOffBits +
                            ((info16.biWidth * 2) + destPadding) * (h - 1));
        }
        readf.close();
        writef.close();
    }

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