How to covert QT QImage into OpenCV IplImage and vise-versa.

 

These days,I am working on developing an application for “High Voltage Electron Microscope”.Basically it takes images from “High Voltage Electron Microscope” and do tomographic reconstruction and 3D reconstruction…etc I use QT4 for user interface and and OpenCV for image processing functionalities and OpenGL as core frameworks.

I came up with big obstacle since it utilise many frameworks and have to handle conversion in between many image-data-structures.Eg : QImage in QT4 , IplImage in OpenCV and some custom image data structure for internal algorithms.

I came up with following conversion between QImage to IplImage.Hope it will helpful to someone whose spending hours on google.

IplImage* QImage2IplImage(QImage *qimg)
{

IplImage *imgHeader = cvCreateImageHeader( cvSize(qimg->width(), qimg->height()), IPL_DEPTH_8U, 4);
imgHeader->imageData = (char*) qimg->bits();

uchar* newdata = (uchar*) malloc(sizeof(uchar) * qimg->byteCount());
memcpy(newdata, qimg->bits(), qimg->byteCount());
imgHeader->imageData = (char*) newdata;
//cvClo
return imgHeader;
}

QImage*  IplImage2QImage(IplImage *iplImg)
{
int h = iplImg->height;
int w = iplImg->width;
int channels = iplImg->nChannels;
QImage *qimg = new QImage(w, h, QImage::Format_ARGB32);
char *data = iplImg->imageData;

for (int y = 0; y < h; y++, data += iplImg->widthStep)
{
for (int x = 0; x < w; x++)
{
char r, g, b, a = 0;
if (channels == 1)
{
r = data[x * channels];
g = data[x * channels];
b = data[x * channels];
}
else if (channels == 3 || channels == 4)
{
r = data[x * channels + 2];
g = data[x * channels + 1];
b = data[x * channels];
}

if (channels == 4)
{
a = data[x * channels + 3];
qimg->setPixel(x, y, qRgba(r, g, b, a));
}
else
{
qimg->setPixel(x, y, qRgb(r, g, b));
}
}
}
return qimg;

}