@app.route('/test',methods=['POST'])
def en():
     b2 = request.files['b2']
     b4 = request.files['b4']
     tmp_fname2 = os.path.join('uploads', uuid4().__str__())
     tmp_fname4 = os.path.join('uploads', uuid4().__str__())
    
     b2.save(tmp_fname2)
     b4.save(tmp_fname4)
     size  = Image.open(tmp_fname2).size
     print(size)

     b2 = cv.imread(tmp_fname2)
     print(np.max(np.array(b2)))
     b4 = cv.imread(tmp_fname4)
     print(np.max(np.array(b4)))

  
     
        #影像运算（+，-，*，/）
     sub = (b2 - b4)*1.0
     sum = (b2 + b4)*1.0

 
     result = cv.divide(sub, sum)
    #结果影像为三波段，取第一波段
     result = result[:,:,0]
     result = (result <= 1) * 255.0 #阈值分割，括号内的result<=1为阈值分割
     data = base64.b64encode(result).decode()
     result = result.astype(np.uint8)
     result = Image.fromarray(result)
     #result.show()
     
    
     os.remove(tmp_fname2)
     os.remove(tmp_fname4)

     imgByteArr = io.BytesIO()
     result.save(imgByteArr,format='TIFF')
     imgByteArr = imgByteArr.getvalue()

     return imgByteArr