there is a way for qt to image mosaicking?

[yeye_olive]

Example, to copy 0th pixel of a specific row from bImage to cImage:

QRgb* bImgLine = (QRgb*)bImage.scanLine(row);
QRgb* cImgLine = (QRgb*)cImage.scanLine(row);
*(cImgLine+40) = *(bImgLine+0);

QRgb* bImgLine = (QRgb*)bImage.scanLine(row);
QRgb* cImgLine = (QRgb*)cImage.scanLine(row);
*(cImgLine+40) = *(bImgLine+0);

To copy to clipboard, switch view to plain text mode 

Be careful, your code assumes that bImage has the same format as cImage (QImage::Format_RGB32). You should convert bImage to that format first.