QImage does not show image correctly as OpenCV does

[feiyuhuahuo]

I'm use the following code to do test.

class PP(QMainWindow):
    def __init__(self):
        super().__init__()
        loader = QUiLoader()
        self.main_ui = loader.load('test.ui')
        self.setCentralWidget(self.main_ui)

        img = cv2.imread('2222.png', cv2.IMREAD_GRAYSCALE)
        cv2.imshow('aa', img)
        cv2.waitKey()

        height, width = img.shape
        print('shape:', img.shape, 'dtype:', img.dtype)
        qimg = QImage(img.astype('uint8').data, width, height, QImage.Format_Grayscale8)

        self.main_ui.label.setPixmap(QPixmap(qimg))
        self.show()


if __name__ == '__main__':
    app = QApplication()
    ui = PP()
    app.exec()

When the image is '2222.png', the widget shows the same as OpenCV does. Th left window is called by OpenCV.

But if I change '2222.png' to another image, the widget shows weirdly. I want the widget (the right window) to show the same as OpenCV does.

The two image are both greyscale image and are both uint8 dtype. But why is the difference?

[J.Hilk]

@feiyuhuahuo
I would say you have some "chunk" data in your file, that is causing an offset in the bytes -> the result is the shifted image. That chunkdata is probably the header. Did you simply change the ending/file extension of your image ?
Seems like opencv does some error corrections., but my guess is your image is not format conform.

[feiyuhuahuo]

@J-Hilk Hi，the two images are saved by OpenCV.Write() function, and I did not simply change the ending/file extension.
I tried another initialization method of QImage.

I modified the code to:
qimg = QImage(img.astype('uint8').data, width, height, width*1, QImage.Format_Grayscale8)
And now the image shows correctly.

Can this exclude that the data of my image is error?