text: import tensorflow as tf
  import tensorflow.keras.layers as nn
  import numpy as np
  import cv2
  
  class Descriptor(tf.keras.layers.Layer) :
  	def __init__(self,dim=256) :
  		super(Descriptor,self).__init__()
  		self.dim=dim
  		self.conv1=nn.Conv2D(256,3,1,padding='same',activation='relu')
  		self.conv2=nn.Conv2D(self.dim,1,1,padding='same')
  
  	def call(self,x) :
  		x=self.conv1(x)
  		x=self.conv2(x)
  		x=tf.math.l2_normalize(x,axis=-1)
  
  		return x
  
  if __name__=='__main__' :
  	desc=Descriptor()
  	x=tf.random.normal(shape=(1,120,120,96))
  	y=desc(x)
  	print(y.shape)