Can getUnconnectedOutLayers() get the variable Width and Height?

Question

I wanted to use this way to do the object detection but somehow the Python can`t detect my width and height, it always show me that variables_undefined errors, but based on others I don't saw this problems appear to them, may I ask what is the problem in my codes?

    ln=yolo.getLayerNames() 
    ln=[ln[i[0]-1] for i in yolo.getUnconnectedOutLayers()] layerOut=yolo.forward(ln)    
    boxs=[]
    confidences=[]
    classIds = []
    
    for outputs in layerOut:
      for detection in outputs:
        score = detection[5:]
        classId=np.argMax(score)
        confidence=score[classId]
        if confidence>0.7:
          centerX=int(detection[0]*width)
          centerY=int(detection[0]*height)
          w=int(detection[0]*width)
          h=int(detection[0]*height)
    
          x=int(centerX-w/2)
          y=int(centerY-w/2)
    
          boxs.append([x,y,w,h])
          confidences.append(float(confidence))
          classIds.append(classId)

I have tried to defined the variables but it seems if I define it the ouptput is incorrect.