Cannot get image texture to display (OpenCV + Kivy)

[Jonathan Piat]

Hi,

i'am creating a kivy app to display OpenCV images acquired in a robotic framework (ROS). The following code display an image in the openCv window but the kivy image stays blank. I have tried examples that displays an image acquired from a webcam using OpenCv and they work so i have no clue of what i do wrong :

     def populate_texture(self, dt):
        print 'calling update '
        try:
            if not self.frame_queue.empty() :
                print 'Queue not empty'
                img = self.frame_queue.get()
                cv2.imshow('img', img)
                cv2.waitKey(1)
                image_texture = Texture.create(size=(img.shape[1], img.shape[0]), colorfmt='bgr')
                image_texture.blit_buffer(img.tostring(), colorfmt='bgr', bufferfmt='ubyte')
                self.subject_picture.texture = image_texture
                self.subject_picture.do_layout()
        except:
            traceback.print_exc()