QImage与IplImage之间的转换

网上很多的QImage与IplImage之间的转换代码，不知道别人能否顺利的用过，但是我是没顺利的使用过。主要问题是图像数据排列问题，最重要的是关注图像数据每行占多少个字节，因为涉及到对齐问题。两种不同的数据结构中都有相关的成员变量来表示，这个必须得统一，否则会发生错位或者segment fault的错误。

嵌入式Linux 中并没有完全实现openCV类库，所以不能正常使用像cvLoadImage这类函数。我的大体思路是使用QT来读入，显示，存储图像，用openCV里的函数来处理识别图像。

使用openCV中绝大部分图像处理函数的输入都是IplImage类型的灰度图像，其中涉及最重要的代码就是QImage与IplImage之间的转换，在借鉴其他网友的代码基础上做了适合自己应用的修改，代码如下：

IplImage *Lplimage2QImage::QImageToIplImageRGB(const QImage * qImage)
{
    int width = qImage->width();
    int height = qImage->height();
    CvSize Size;
    Size.height = height;
    Size.width = width;
    IplImage *IplImageBuffer = cvCreateImage(Size, IPL_DEPTH_8U, 3);
    for (int y = 0; y < height; ++y)
    {
        for (int x = 0; x < width; ++x)
        {
            QRgb rgb = qImage->pixel(x, y);
            cvSet2D(IplImageBuffer, y, x, CV_RGB(qRed(rgb), qGreen(rgb), qBlue(rgb)));
        }
    }
    return IplImageBuffer;
}


IplImage *Lplimage2QImage::QImageToIplImageGray(const QImage * qImage)
{
    int width = qImage->width();
    int height = qImage->height();
    int widthStep = 0;

    CvSize Size;
    Size.height = height;
    Size.width = width;

    IplImage *charIplImageBuffer = cvCreateImage(Size, IPL_DEPTH_8U, 1);
    widthStep = charIplImageBuffer->widthStep;
    char *charTemp = (char *) charIplImageBuffer->imageData;

    for (int y = 0; y < height; ++y)
    {
        for (int x = 0; x < width; ++x)
        {
            int index = y * widthStep + x;
            charTemp[index] = (char) qGray(qImage->pixel(x, y));
        }
    }

    return charIplImageBuffer;
}


QImage *Lplimage2QImage::IplImageToQImageGray(const IplImage * iplImage)
{
    int width = iplImage->width;
    int widthStep = iplImage->widthStep;
    int height = iplImage->height;

    QImage *qImage = new QImage((uchar*)iplImage->imageData,width,height, \
                                        widthStep,QImage::Format_Indexed8);
    QVector<QRgb> grayColourTable;
    for(int i = 0; i < 256; i++)
       grayColourTable.append(qRgb(i, i, i));
    qImage->setColorTable(grayColourTable);
    return qImage;
}

QImage *Lplimage2QImage::IplImageToQImageRGB(const IplImage * iplImage)
{
    int width = iplImage->width;
    int widthStep = iplImage->widthStep;
    int height = iplImage->height;

    uchar *qImageBuffer = (uchar *) malloc(width*height*4*sizeof(uchar));
    uchar *QImagePtr = qImageBuffer;
    const uchar *iplImagePtr = (const uchar *) iplImage->imageData;
    for (int y = 0; y < height; y++)
    {
        for (int x = 0; x < width; x++)
        {
            QImagePtr[0] = iplImagePtr[0];
            QImagePtr[1] = iplImagePtr[1];
            QImagePtr[2] = iplImagePtr[2];
            QImagePtr[3] = 0;

            QImagePtr += 4;
            iplImagePtr += 3;
        }
    iplImagePtr += widthStep-3*width;
    }
    QImage *qImage = new QImage(qImageBuffer, width, height, QImage::Format_RGB32);
    return qImage;

}