Deep Learning based Background Removal from Images using TensorFlow and Python

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In this tutorial, we are going to learn how to use deep learning to remove background from images with TensorFlow. In short, we’ll use DeepLabV3+, a semantic segmentation based model to extract the background and foreground mask from the image. We are going to use these masks to extract the background from the image and leave the foreground intact.


Introduction

Image background removal is a popular task in the computer vision community. It is used to alter the background in images for a better user experience. For example, while clicking a selfie, you can blur the background (bokeh) using the portrait effect of the camera. This portrait effect is generated by extracting the background from the original image.

An example of the portrait effect.
An example of the portrait effect. Source: https://ai.googleblog.com/2017/10/portrait-mode-on-pixel-2-and-pixel-2-xl.html

Here, we are going to use semantic segmentation algorithms for segmenting the background from images and applying it to alter the background. For this task, we are going to use the DeepLabV3+ architecture, which is trained on human image segmentation.

An example image and binary mask from the Human Image Segmentation dataset.
An example image and binary mask from the Human Image Segmentation dataset.

To learn about the training of DeepLabV3+ on Human Image Segmentation, check the links:

YouTube Tutorial

Watch the video for a better explanation of the process of “Remove Photo Background using Deep Learning in Python.”

The entire process of background removal:

  1. Loading the trained DeepLabV3+ model in TensorFlow.
  2. Loading and reading all the images.
  3. Predicting the mask for all these images.
  4. Extracting the background and foreground mask.
  5. Using the masks to remove or change the background.

Implementation

In the beginning, we import all the required classes, functions other stuff.

import os
os.environ["TF_CPP_MIN_LOG_LEVEL"] = "2"

import numpy as np
import cv2
from glob import glob
from tqdm import tqdm
import tensorflow as tf
from tensorflow.keras.utils import CustomObjectScope
from metrics import dice_loss, dice_coef, 

Next, we define height and width as global parameters.

H = 512
W = 512

Here, we define a function name create_dir. This function would help in creating a folder or a directory.

def create_dir(path):
    if not os.path.exists(path):
        os.makedirs(path)

Next, we are going to seed the environment to make sure that things are reproducible. While training the DeepLabV3+ model, we have used the same seed.

 np.random.seed(42)
 tf.random.set_seed(42)

Now, we are going to create an empty directory called remove_bg. This directory is used to store the processed images.

create_dir("remove_bg")

Here, we load the trained DeepLabV3+ model using the TensorFlow functions.

with CustomObjectScope({'iou': iou, 'dice_coef': dice_coef, 'dice_loss': dice_loss}):
        model = tf.keras.models.load_model("model.h5")

As we have loaded the trained model, we are going to take a look at the model summary.

 model.summary()
Model: "functional_1"
__________________________________________________________________________________________________
Layer (type)                    Output Shape         Param #     Connected to                     
==================================================================================================
input_1 (InputLayer)            [(None, 512, 512, 3) 0                                            
__________________________________________________________________________________________________
conv1_pad (ZeroPadding2D)       (None, 518, 518, 3)  0           input_1[0][0]                    
__________________________________________________________________________________________________
conv1_conv (Conv2D)             (None, 256, 256, 64) 9472        conv1_pad[0][0]                  
__________________________________________________________________________________________________
conv1_bn (BatchNormalization)   (None, 256, 256, 64) 256         conv1_conv[0][0]                 
__________________________________________________________________________________________________
conv1_relu (Activation)         (None, 256, 256, 64) 0           conv1_bn[0][0]                   
__________________________________________________________________________________________________
pool1_pad (ZeroPadding2D)       (None, 258, 258, 64) 0           conv1_relu[0][0]                 
__________________________________________________________________________________________________
pool1_pool (MaxPooling2D)       (None, 128, 128, 64) 0           pool1_pad[0][0]                  
__________________________________________________________________________________________________
conv2_block1_1_conv (Conv2D)    (None, 128, 128, 64) 4160        pool1_pool[0][0]                 
__________________________________________________________________________________________________
conv2_block1_1_bn (BatchNormali (None, 128, 128, 64) 256         conv2_block1_1_conv[0][0]        
__________________________________________________________________________________________________
conv2_block1_1_relu (Activation (None, 128, 128, 64) 0           conv2_block1_1_bn[0][0]          
__________________________________________________________________________________________________
conv2_block1_2_conv (Conv2D)    (None, 128, 128, 64) 36928       conv2_block1_1_relu[0][0]        
__________________________________________________________________________________________________
conv2_block1_2_bn (BatchNormali (None, 128, 128, 64) 256         conv2_block1_2_conv[0][0]        
__________________________________________________________________________________________________
conv2_block1_2_relu (Activation (None, 128, 128, 64) 0           conv2_block1_2_bn[0][0]          
__________________________________________________________________________________________________
conv2_block1_0_conv (Conv2D)    (None, 128, 128, 256 16640       pool1_pool[0][0]                 
__________________________________________________________________________________________________
conv2_block1_3_conv (Conv2D)    (None, 128, 128, 256 16640       conv2_block1_2_relu[0][0]        
__________________________________________________________________________________________________
conv2_block1_0_bn (BatchNormali (None, 128, 128, 256 1024        conv2_block1_0_conv[0][0]        
__________________________________________________________________________________________________
conv2_block1_3_bn (BatchNormali (None, 128, 128, 256 1024        conv2_block1_3_conv[0][0]        
__________________________________________________________________________________________________
conv2_block1_add (Add)          (None, 128, 128, 256 0           conv2_block1_0_bn[0][0]          
                                                                 conv2_block1_3_bn[0][0]          
__________________________________________________________________________________________________
conv2_block1_out (Activation)   (None, 128, 128, 256 0           conv2_block1_add[0][0]           
__________________________________________________________________________________________________
conv2_block2_1_conv (Conv2D)    (None, 128, 128, 64) 16448       conv2_block1_out[0][0]           
__________________________________________________________________________________________________
conv2_block2_1_bn (BatchNormali (None, 128, 128, 64) 256         conv2_block2_1_conv[0][0]        
__________________________________________________________________________________________________
conv2_block2_1_relu (Activation (None, 128, 128, 64) 0           conv2_block2_1_bn[0][0]          
__________________________________________________________________________________________________
conv2_block2_2_conv (Conv2D)    (None, 128, 128, 64) 36928       conv2_block2_1_relu[0][0]        
__________________________________________________________________________________________________
conv2_block2_2_bn (BatchNormali (None, 128, 128, 64) 256         conv2_block2_2_conv[0][0]        
__________________________________________________________________________________________________
conv2_block2_2_relu (Activation (None, 128, 128, 64) 0           conv2_block2_2_bn[0][0]          
__________________________________________________________________________________________________
conv2_block2_3_conv (Conv2D)    (None, 128, 128, 256 16640       conv2_block2_2_relu[0][0]        
__________________________________________________________________________________________________
conv2_block2_3_bn (BatchNormali (None, 128, 128, 256 1024        conv2_block2_3_conv[0][0]        
__________________________________________________________________________________________________
conv2_block2_add (Add)          (None, 128, 128, 256 0           conv2_block1_out[0][0]           
                                                                 conv2_block2_3_bn[0][0]          
__________________________________________________________________________________________________
conv2_block2_out (Activation)   (None, 128, 128, 256 0           conv2_block2_add[0][0]           
__________________________________________________________________________________________________
conv2_block3_1_conv (Conv2D)    (None, 128, 128, 64) 16448       conv2_block2_out[0][0]           
__________________________________________________________________________________________________
conv2_block3_1_bn (BatchNormali (None, 128, 128, 64) 256         conv2_block3_1_conv[0][0]        
__________________________________________________________________________________________________
conv2_block3_1_relu (Activation (None, 128, 128, 64) 0           conv2_block3_1_bn[0][0]          
__________________________________________________________________________________________________
conv2_block3_2_conv (Conv2D)    (None, 128, 128, 64) 36928       conv2_block3_1_relu[0][0]        
__________________________________________________________________________________________________
conv2_block3_2_bn (BatchNormali (None, 128, 128, 64) 256         conv2_block3_2_conv[0][0]        
__________________________________________________________________________________________________
conv2_block3_2_relu (Activation (None, 128, 128, 64) 0           conv2_block3_2_bn[0][0]          
__________________________________________________________________________________________________
conv2_block3_3_conv (Conv2D)    (None, 128, 128, 256 16640       conv2_block3_2_relu[0][0]        
__________________________________________________________________________________________________
conv2_block3_3_bn (BatchNormali (None, 128, 128, 256 1024        conv2_block3_3_conv[0][0]        
__________________________________________________________________________________________________
conv2_block3_add (Add)          (None, 128, 128, 256 0           conv2_block2_out[0][0]           
                                                                 conv2_block3_3_bn[0][0]          
__________________________________________________________________________________________________
conv2_block3_out (Activation)   (None, 128, 128, 256 0           conv2_block3_add[0][0]           
__________________________________________________________________________________________________
conv3_block1_1_conv (Conv2D)    (None, 64, 64, 128)  32896       conv2_block3_out[0][0]           
__________________________________________________________________________________________________
conv3_block1_1_bn (BatchNormali (None, 64, 64, 128)  512         conv3_block1_1_conv[0][0]        
__________________________________________________________________________________________________
conv3_block1_1_relu (Activation (None, 64, 64, 128)  0           conv3_block1_1_bn[0][0]          
__________________________________________________________________________________________________
conv3_block1_2_conv (Conv2D)    (None, 64, 64, 128)  147584      conv3_block1_1_relu[0][0]        
__________________________________________________________________________________________________
conv3_block1_2_bn (BatchNormali (None, 64, 64, 128)  512         conv3_block1_2_conv[0][0]        
__________________________________________________________________________________________________
conv3_block1_2_relu (Activation (None, 64, 64, 128)  0           conv3_block1_2_bn[0][0]          
__________________________________________________________________________________________________
conv3_block1_0_conv (Conv2D)    (None, 64, 64, 512)  131584      conv2_block3_out[0][0]           
__________________________________________________________________________________________________
conv3_block1_3_conv (Conv2D)    (None, 64, 64, 512)  66048       conv3_block1_2_relu[0][0]        
__________________________________________________________________________________________________
conv3_block1_0_bn (BatchNormali (None, 64, 64, 512)  2048        conv3_block1_0_conv[0][0]        
__________________________________________________________________________________________________
conv3_block1_3_bn (BatchNormali (None, 64, 64, 512)  2048        conv3_block1_3_conv[0][0]        
__________________________________________________________________________________________________
conv3_block1_add (Add)          (None, 64, 64, 512)  0           conv3_block1_0_bn[0][0]          
                                                                 conv3_block1_3_bn[0][0]          
__________________________________________________________________________________________________
conv3_block1_out (Activation)   (None, 64, 64, 512)  0           conv3_block1_add[0][0]           
__________________________________________________________________________________________________
conv3_block2_1_conv (Conv2D)    (None, 64, 64, 128)  65664       conv3_block1_out[0][0]           
__________________________________________________________________________________________________
conv3_block2_1_bn (BatchNormali (None, 64, 64, 128)  512         conv3_block2_1_conv[0][0]        
__________________________________________________________________________________________________
conv3_block2_1_relu (Activation (None, 64, 64, 128)  0           conv3_block2_1_bn[0][0]          
__________________________________________________________________________________________________
conv3_block2_2_conv (Conv2D)    (None, 64, 64, 128)  147584      conv3_block2_1_relu[0][0]        
__________________________________________________________________________________________________
conv3_block2_2_bn (BatchNormali (None, 64, 64, 128)  512         conv3_block2_2_conv[0][0]        
__________________________________________________________________________________________________
conv3_block2_2_relu (Activation (None, 64, 64, 128)  0           conv3_block2_2_bn[0][0]          
__________________________________________________________________________________________________
conv3_block2_3_conv (Conv2D)    (None, 64, 64, 512)  66048       conv3_block2_2_relu[0][0]        
__________________________________________________________________________________________________
conv3_block2_3_bn (BatchNormali (None, 64, 64, 512)  2048        conv3_block2_3_conv[0][0]        
__________________________________________________________________________________________________
conv3_block2_add (Add)          (None, 64, 64, 512)  0           conv3_block1_out[0][0]           
                                                                 conv3_block2_3_bn[0][0]          
__________________________________________________________________________________________________
conv3_block2_out (Activation)   (None, 64, 64, 512)  0           conv3_block2_add[0][0]           
__________________________________________________________________________________________________
conv3_block3_1_conv (Conv2D)    (None, 64, 64, 128)  65664       conv3_block2_out[0][0]           
__________________________________________________________________________________________________
conv3_block3_1_bn (BatchNormali (None, 64, 64, 128)  512         conv3_block3_1_conv[0][0]        
__________________________________________________________________________________________________
conv3_block3_1_relu (Activation (None, 64, 64, 128)  0           conv3_block3_1_bn[0][0]          
__________________________________________________________________________________________________
conv3_block3_2_conv (Conv2D)    (None, 64, 64, 128)  147584      conv3_block3_1_relu[0][0]        
__________________________________________________________________________________________________
conv3_block3_2_bn (BatchNormali (None, 64, 64, 128)  512         conv3_block3_2_conv[0][0]        
__________________________________________________________________________________________________
conv3_block3_2_relu (Activation (None, 64, 64, 128)  0           conv3_block3_2_bn[0][0]          
__________________________________________________________________________________________________
conv3_block3_3_conv (Conv2D)    (None, 64, 64, 512)  66048       conv3_block3_2_relu[0][0]        
__________________________________________________________________________________________________
conv3_block3_3_bn (BatchNormali (None, 64, 64, 512)  2048        conv3_block3_3_conv[0][0]        
__________________________________________________________________________________________________
conv3_block3_add (Add)          (None, 64, 64, 512)  0           conv3_block2_out[0][0]           
                                                                 conv3_block3_3_bn[0][0]          
__________________________________________________________________________________________________
conv3_block3_out (Activation)   (None, 64, 64, 512)  0           conv3_block3_add[0][0]           
__________________________________________________________________________________________________
conv3_block4_1_conv (Conv2D)    (None, 64, 64, 128)  65664       conv3_block3_out[0][0]           
__________________________________________________________________________________________________
conv3_block4_1_bn (BatchNormali (None, 64, 64, 128)  512         conv3_block4_1_conv[0][0]        
__________________________________________________________________________________________________
conv3_block4_1_relu (Activation (None, 64, 64, 128)  0           conv3_block4_1_bn[0][0]          
__________________________________________________________________________________________________
conv3_block4_2_conv (Conv2D)    (None, 64, 64, 128)  147584      conv3_block4_1_relu[0][0]        
__________________________________________________________________________________________________
conv3_block4_2_bn (BatchNormali (None, 64, 64, 128)  512         conv3_block4_2_conv[0][0]        
__________________________________________________________________________________________________
conv3_block4_2_relu (Activation (None, 64, 64, 128)  0           conv3_block4_2_bn[0][0]          
__________________________________________________________________________________________________
conv3_block4_3_conv (Conv2D)    (None, 64, 64, 512)  66048       conv3_block4_2_relu[0][0]        
__________________________________________________________________________________________________
conv3_block4_3_bn (BatchNormali (None, 64, 64, 512)  2048        conv3_block4_3_conv[0][0]        
__________________________________________________________________________________________________
conv3_block4_add (Add)          (None, 64, 64, 512)  0           conv3_block3_out[0][0]           
                                                                 conv3_block4_3_bn[0][0]          
__________________________________________________________________________________________________
conv3_block4_out (Activation)   (None, 64, 64, 512)  0           conv3_block4_add[0][0]           
__________________________________________________________________________________________________
conv4_block1_1_conv (Conv2D)    (None, 32, 32, 256)  131328      conv3_block4_out[0][0]           
__________________________________________________________________________________________________
conv4_block1_1_bn (BatchNormali (None, 32, 32, 256)  1024        conv4_block1_1_conv[0][0]        
__________________________________________________________________________________________________
conv4_block1_1_relu (Activation (None, 32, 32, 256)  0           conv4_block1_1_bn[0][0]          
__________________________________________________________________________________________________
conv4_block1_2_conv (Conv2D)    (None, 32, 32, 256)  590080      conv4_block1_1_relu[0][0]        
__________________________________________________________________________________________________
conv4_block1_2_bn (BatchNormali (None, 32, 32, 256)  1024        conv4_block1_2_conv[0][0]        
__________________________________________________________________________________________________
conv4_block1_2_relu (Activation (None, 32, 32, 256)  0           conv4_block1_2_bn[0][0]          
__________________________________________________________________________________________________
conv4_block1_0_conv (Conv2D)    (None, 32, 32, 1024) 525312      conv3_block4_out[0][0]           
__________________________________________________________________________________________________
conv4_block1_3_conv (Conv2D)    (None, 32, 32, 1024) 263168      conv4_block1_2_relu[0][0]        
__________________________________________________________________________________________________
conv4_block1_0_bn (BatchNormali (None, 32, 32, 1024) 4096        conv4_block1_0_conv[0][0]        
__________________________________________________________________________________________________
conv4_block1_3_bn (BatchNormali (None, 32, 32, 1024) 4096        conv4_block1_3_conv[0][0]        
__________________________________________________________________________________________________
conv4_block1_add (Add)          (None, 32, 32, 1024) 0           conv4_block1_0_bn[0][0]          
                                                                 conv4_block1_3_bn[0][0]          
__________________________________________________________________________________________________
conv4_block1_out (Activation)   (None, 32, 32, 1024) 0           conv4_block1_add[0][0]           
__________________________________________________________________________________________________
conv4_block2_1_conv (Conv2D)    (None, 32, 32, 256)  262400      conv4_block1_out[0][0]           
__________________________________________________________________________________________________
conv4_block2_1_bn (BatchNormali (None, 32, 32, 256)  1024        conv4_block2_1_conv[0][0]        
__________________________________________________________________________________________________
conv4_block2_1_relu (Activation (None, 32, 32, 256)  0           conv4_block2_1_bn[0][0]          
__________________________________________________________________________________________________
conv4_block2_2_conv (Conv2D)    (None, 32, 32, 256)  590080      conv4_block2_1_relu[0][0]        
__________________________________________________________________________________________________
conv4_block2_2_bn (BatchNormali (None, 32, 32, 256)  1024        conv4_block2_2_conv[0][0]        
__________________________________________________________________________________________________
conv4_block2_2_relu (Activation (None, 32, 32, 256)  0           conv4_block2_2_bn[0][0]          
__________________________________________________________________________________________________
conv4_block2_3_conv (Conv2D)    (None, 32, 32, 1024) 263168      conv4_block2_2_relu[0][0]        
__________________________________________________________________________________________________
conv4_block2_3_bn (BatchNormali (None, 32, 32, 1024) 4096        conv4_block2_3_conv[0][0]        
__________________________________________________________________________________________________
conv4_block2_add (Add)          (None, 32, 32, 1024) 0           conv4_block1_out[0][0]           
                                                                 conv4_block2_3_bn[0][0]          
__________________________________________________________________________________________________
conv4_block2_out (Activation)   (None, 32, 32, 1024) 0           conv4_block2_add[0][0]           
__________________________________________________________________________________________________
conv4_block3_1_conv (Conv2D)    (None, 32, 32, 256)  262400      conv4_block2_out[0][0]           
__________________________________________________________________________________________________
conv4_block3_1_bn (BatchNormali (None, 32, 32, 256)  1024        conv4_block3_1_conv[0][0]        
__________________________________________________________________________________________________
conv4_block3_1_relu (Activation (None, 32, 32, 256)  0           conv4_block3_1_bn[0][0]          
__________________________________________________________________________________________________
conv4_block3_2_conv (Conv2D)    (None, 32, 32, 256)  590080      conv4_block3_1_relu[0][0]        
__________________________________________________________________________________________________
conv4_block3_2_bn (BatchNormali (None, 32, 32, 256)  1024        conv4_block3_2_conv[0][0]        
__________________________________________________________________________________________________
conv4_block3_2_relu (Activation (None, 32, 32, 256)  0           conv4_block3_2_bn[0][0]          
__________________________________________________________________________________________________
conv4_block3_3_conv (Conv2D)    (None, 32, 32, 1024) 263168      conv4_block3_2_relu[0][0]        
__________________________________________________________________________________________________
conv4_block3_3_bn (BatchNormali (None, 32, 32, 1024) 4096        conv4_block3_3_conv[0][0]        
__________________________________________________________________________________________________
conv4_block3_add (Add)          (None, 32, 32, 1024) 0           conv4_block2_out[0][0]           
                                                                 conv4_block3_3_bn[0][0]          
__________________________________________________________________________________________________
conv4_block3_out (Activation)   (None, 32, 32, 1024) 0           conv4_block3_add[0][0]           
__________________________________________________________________________________________________
conv4_block4_1_conv (Conv2D)    (None, 32, 32, 256)  262400      conv4_block3_out[0][0]           
__________________________________________________________________________________________________
conv4_block4_1_bn (BatchNormali (None, 32, 32, 256)  1024        conv4_block4_1_conv[0][0]        
__________________________________________________________________________________________________
conv4_block4_1_relu (Activation (None, 32, 32, 256)  0           conv4_block4_1_bn[0][0]          
__________________________________________________________________________________________________
conv4_block4_2_conv (Conv2D)    (None, 32, 32, 256)  590080      conv4_block4_1_relu[0][0]        
__________________________________________________________________________________________________
conv4_block4_2_bn (BatchNormali (None, 32, 32, 256)  1024        conv4_block4_2_conv[0][0]        
__________________________________________________________________________________________________
conv4_block4_2_relu (Activation (None, 32, 32, 256)  0           conv4_block4_2_bn[0][0]          
__________________________________________________________________________________________________
conv4_block4_3_conv (Conv2D)    (None, 32, 32, 1024) 263168      conv4_block4_2_relu[0][0]        
__________________________________________________________________________________________________
conv4_block4_3_bn (BatchNormali (None, 32, 32, 1024) 4096        conv4_block4_3_conv[0][0]        
__________________________________________________________________________________________________
conv4_block4_add (Add)          (None, 32, 32, 1024) 0           conv4_block3_out[0][0]           
                                                                 conv4_block4_3_bn[0][0]          
__________________________________________________________________________________________________
conv4_block4_out (Activation)   (None, 32, 32, 1024) 0           conv4_block4_add[0][0]           
__________________________________________________________________________________________________
conv4_block5_1_conv (Conv2D)    (None, 32, 32, 256)  262400      conv4_block4_out[0][0]           
__________________________________________________________________________________________________
conv4_block5_1_bn (BatchNormali (None, 32, 32, 256)  1024        conv4_block5_1_conv[0][0]        
__________________________________________________________________________________________________
conv4_block5_1_relu (Activation (None, 32, 32, 256)  0           conv4_block5_1_bn[0][0]          
__________________________________________________________________________________________________
conv4_block5_2_conv (Conv2D)    (None, 32, 32, 256)  590080      conv4_block5_1_relu[0][0]        
__________________________________________________________________________________________________
conv4_block5_2_bn (BatchNormali (None, 32, 32, 256)  1024        conv4_block5_2_conv[0][0]        
__________________________________________________________________________________________________
conv4_block5_2_relu (Activation (None, 32, 32, 256)  0           conv4_block5_2_bn[0][0]          
__________________________________________________________________________________________________
conv4_block5_3_conv (Conv2D)    (None, 32, 32, 1024) 263168      conv4_block5_2_relu[0][0]        
__________________________________________________________________________________________________
conv4_block5_3_bn (BatchNormali (None, 32, 32, 1024) 4096        conv4_block5_3_conv[0][0]        
__________________________________________________________________________________________________
conv4_block5_add (Add)          (None, 32, 32, 1024) 0           conv4_block4_out[0][0]           
                                                                 conv4_block5_3_bn[0][0]          
__________________________________________________________________________________________________
conv4_block5_out (Activation)   (None, 32, 32, 1024) 0           conv4_block5_add[0][0]           
__________________________________________________________________________________________________
conv4_block6_1_conv (Conv2D)    (None, 32, 32, 256)  262400      conv4_block5_out[0][0]           
__________________________________________________________________________________________________
conv4_block6_1_bn (BatchNormali (None, 32, 32, 256)  1024        conv4_block6_1_conv[0][0]        
__________________________________________________________________________________________________
conv4_block6_1_relu (Activation (None, 32, 32, 256)  0           conv4_block6_1_bn[0][0]          
__________________________________________________________________________________________________
conv4_block6_2_conv (Conv2D)    (None, 32, 32, 256)  590080      conv4_block6_1_relu[0][0]        
__________________________________________________________________________________________________
conv4_block6_2_bn (BatchNormali (None, 32, 32, 256)  1024        conv4_block6_2_conv[0][0]        
__________________________________________________________________________________________________
conv4_block6_2_relu (Activation (None, 32, 32, 256)  0           conv4_block6_2_bn[0][0]          
__________________________________________________________________________________________________
conv4_block6_3_conv (Conv2D)    (None, 32, 32, 1024) 263168      conv4_block6_2_relu[0][0]        
__________________________________________________________________________________________________
conv4_block6_3_bn (BatchNormali (None, 32, 32, 1024) 4096        conv4_block6_3_conv[0][0]        
__________________________________________________________________________________________________
conv4_block6_add (Add)          (None, 32, 32, 1024) 0           conv4_block5_out[0][0]           
                                                                 conv4_block6_3_bn[0][0]          
__________________________________________________________________________________________________
conv4_block6_out (Activation)   (None, 32, 32, 1024) 0           conv4_block6_add[0][0]           
__________________________________________________________________________________________________
average_pooling (AveragePooling (None, 1, 1, 1024)   0           conv4_block6_out[0][0]           
__________________________________________________________________________________________________
conv2d (Conv2D)                 (None, 1, 1, 256)    262144      average_pooling[0][0]            
__________________________________________________________________________________________________
bn_1 (BatchNormalization)       (None, 1, 1, 256)    1024        conv2d[0][0]                     
__________________________________________________________________________________________________
conv2d_1 (Conv2D)               (None, 32, 32, 256)  262144      conv4_block6_out[0][0]           
__________________________________________________________________________________________________
conv2d_2 (Conv2D)               (None, 32, 32, 256)  2359296     conv4_block6_out[0][0]           
__________________________________________________________________________________________________
conv2d_3 (Conv2D)               (None, 32, 32, 256)  2359296     conv4_block6_out[0][0]           
__________________________________________________________________________________________________
conv2d_4 (Conv2D)               (None, 32, 32, 256)  2359296     conv4_block6_out[0][0]           
__________________________________________________________________________________________________
relu_1 (Activation)             (None, 1, 1, 256)    0           bn_1[0][0]                       
__________________________________________________________________________________________________
batch_normalization (BatchNorma (None, 32, 32, 256)  1024        conv2d_1[0][0]                   
__________________________________________________________________________________________________
batch_normalization_1 (BatchNor (None, 32, 32, 256)  1024        conv2d_2[0][0]                   
__________________________________________________________________________________________________
batch_normalization_2 (BatchNor (None, 32, 32, 256)  1024        conv2d_3[0][0]                   
__________________________________________________________________________________________________
batch_normalization_3 (BatchNor (None, 32, 32, 256)  1024        conv2d_4[0][0]                   
__________________________________________________________________________________________________
up_sampling2d (UpSampling2D)    (None, 32, 32, 256)  0           relu_1[0][0]                     
__________________________________________________________________________________________________
activation (Activation)         (None, 32, 32, 256)  0           batch_normalization[0][0]        
__________________________________________________________________________________________________
activation_1 (Activation)       (None, 32, 32, 256)  0           batch_normalization_1[0][0]      
__________________________________________________________________________________________________
activation_2 (Activation)       (None, 32, 32, 256)  0           batch_normalization_2[0][0]      
__________________________________________________________________________________________________
activation_3 (Activation)       (None, 32, 32, 256)  0           batch_normalization_3[0][0]      
__________________________________________________________________________________________________
concatenate (Concatenate)       (None, 32, 32, 1280) 0           up_sampling2d[0][0]              
                                                                 activation[0][0]                 
                                                                 activation_1[0][0]               
                                                                 activation_2[0][0]               
                                                                 activation_3[0][0]               
__________________________________________________________________________________________________
conv2d_5 (Conv2D)               (None, 32, 32, 256)  327680      concatenate[0][0]                
__________________________________________________________________________________________________
batch_normalization_4 (BatchNor (None, 32, 32, 256)  1024        conv2d_5[0][0]                   
__________________________________________________________________________________________________
conv2d_6 (Conv2D)               (None, 128, 128, 48) 12288       conv2_block2_out[0][0]           
__________________________________________________________________________________________________
activation_4 (Activation)       (None, 32, 32, 256)  0           batch_normalization_4[0][0]      
__________________________________________________________________________________________________
batch_normalization_5 (BatchNor (None, 128, 128, 48) 192         conv2d_6[0][0]                   
__________________________________________________________________________________________________
up_sampling2d_1 (UpSampling2D)  (None, 128, 128, 256 0           activation_4[0][0]               
__________________________________________________________________________________________________
activation_5 (Activation)       (None, 128, 128, 48) 0           batch_normalization_5[0][0]      
__________________________________________________________________________________________________
concatenate_1 (Concatenate)     (None, 128, 128, 304 0           up_sampling2d_1[0][0]            
                                                                 activation_5[0][0]               
__________________________________________________________________________________________________
global_average_pooling2d (Globa (None, 304)          0           concatenate_1[0][0]              
__________________________________________________________________________________________________
reshape (Reshape)               (None, 1, 1, 304)    0           global_average_pooling2d[0][0]   
__________________________________________________________________________________________________
dense (Dense)                   (None, 1, 1, 38)     11552       reshape[0][0]                    
__________________________________________________________________________________________________
dense_1 (Dense)                 (None, 1, 1, 304)    11552       dense[0][0]                      
__________________________________________________________________________________________________
tf_op_layer_Mul (TensorFlowOpLa (None, 128, 128, 304 0           concatenate_1[0][0]              
                                                                 dense_1[0][0]                    
__________________________________________________________________________________________________
conv2d_7 (Conv2D)               (None, 128, 128, 256 700416      tf_op_layer_Mul[0][0]            
__________________________________________________________________________________________________
batch_normalization_6 (BatchNor (None, 128, 128, 256 1024        conv2d_7[0][0]                   
__________________________________________________________________________________________________
activation_6 (Activation)       (None, 128, 128, 256 0           batch_normalization_6[0][0]      
__________________________________________________________________________________________________
conv2d_8 (Conv2D)               (None, 128, 128, 256 589824      activation_6[0][0]               
__________________________________________________________________________________________________
batch_normalization_7 (BatchNor (None, 128, 128, 256 1024        conv2d_8[0][0]                   
__________________________________________________________________________________________________
activation_7 (Activation)       (None, 128, 128, 256 0           batch_normalization_7[0][0]      
__________________________________________________________________________________________________
global_average_pooling2d_1 (Glo (None, 256)          0           activation_7[0][0]               
__________________________________________________________________________________________________
reshape_1 (Reshape)             (None, 1, 1, 256)    0           global_average_pooling2d_1[0][0] 
__________________________________________________________________________________________________
dense_2 (Dense)                 (None, 1, 1, 32)     8192        reshape_1[0][0]                  
__________________________________________________________________________________________________
dense_3 (Dense)                 (None, 1, 1, 256)    8192        dense_2[0][0]                    
__________________________________________________________________________________________________
tf_op_layer_Mul_1 (TensorFlowOp (None, 128, 128, 256 0           activation_7[0][0]               
                                                                 dense_3[0][0]                    
__________________________________________________________________________________________________
up_sampling2d_2 (UpSampling2D)  (None, 512, 512, 256 0           tf_op_layer_Mul_1[0][0]          
__________________________________________________________________________________________________
output_layer (Conv2D)           (None, 512, 512, 1)  257         up_sampling2d_2[0][0]            
__________________________________________________________________________________________________
activation_8 (Activation)       (None, 512, 512, 1)  0           output_layer[0][0]               
==================================================================================================
Total params: 17,869,697
Trainable params: 17,834,913
Non-trainable params: 34,784

Now, we select all the images, whose background needs to be removed.

data_x = glob("images/*")

Next, we are going to loop over all the images and try to extract the name from the image path.

for path in tqdm(data_x, total=len(data_x)):
     """ Extracting name """
     name = path.split("/")[-1].split(".")[0]

Here, we read the image as an RGB using the OpenCV.

     """ Read the image """
     image = cv2.imread(path, cv2.IMREAD_COLOR)
     h, w, _ = image.shape
     x = cv2.resize(image, (W, H))
     x = x/255.0
     x = x.astype(np.float32)
     x = np.expand_dims(x, axis=0)

In the above code, we do the following:

  1. Give the image path to OpenCV cv2.imread fuction to read the image as RGB.
  2. We save the original height and width of the image before resizing.
  3. Resizing the image to 512 x 512 pixels.
  4. Normalizaing all the pixel values, by dividing it with 255.0 i.e., maximum pixel value.
  5. Change the datatype of the image numpy array to float32.
  6. Expand the dimension of the numpy array on the first axis. [512 x 512 x 3] TO [1 x 512 x 512 x 3]

The processed original image is now fed to the DeepLabV3+ model as input, which predicts the binary mask.

     """ Prediction """
     y = model.predict(x)[0]
     y = cv2.resize(y, (w, h))
     y = np.expand_dims(y, axis=-1)
     y = y > 0.5

     photo_mask = y
     background_mask = np.abs(1-y)

In the above code, we perform the following:

  1. Predict the mask.
  2. Resize the predicting mask to original height and width. [512 x 512] TO [h x w]
  3. Expanding the dimension on the last axis.
  4. As the mask contains the pixel value between the range of 0 and 1. So, we apply 0.5 as the threshold value to convert the pixel value to either 0 or 1.
  5. The photo_mask (predicted mask) is for the segmenting the human or person present within the image.
  6. The background_mask is for segmenting the background region of the image. It is generated by inversing the photo_mask.
An example image.

The above image is used as an input, resized and passed to the trained DeepLabV3+ model. Now, we are going to take a look at them:

  1. Foreground Mask (photo_mask)
  2. Background Mask (background_mask)
    cv2.imwrite(f"remove_bg/{name}.png", photo_mask*255)
    cv2.imwrite(f"remove_bg/{name}.png", background_mask*255)
Foreground and background mask for the original image.
Foreground and background mask for the original image.
    cv2.imwrite(f"remove_bg/{name}.png", image * photo_mask)
    cv2.imwrite(f"remove_bg/{name}.png", image * background_mask)
Foreground image and the background extracted from the original image.
Foreground image and the background extracted from the original image.
    masked_photo = image * photo_mask
    background_mask = np.concatenate([background_mask, background_mask, background_mask], axis=-1)
    background_mask = background_mask * [0, 0, 255]
    final_photo = masked_photo + background_mask
    cv2.imwrite(f"remove_bg/{name}.png", final_photo)

In the above code:

  1. Element-wise multiplication between the original image and the foreground mask (photo_mask) to extract the foreground image.
  2. Concatenate three background_mask (numpy array) to convert it from [H x W x 1] to [H x W x 3].
  3. Multiply the background mask with the required color code in the BGR format. Here, we specified the RED [0, 0, 255].
  4. Add the foreground image and background mask with RED color.
  5. Saving the image.
Two examples of the image where the background was removed and then changes to red color.
Two examples of the image where the background was removed and then changes to red color.

Summary

In this tutorial, we have learned to remove background from human images using a semantic segmentation model known as DeepLabV3+.

If you have any questions or queries. Contact me:

IDIOT DEVELOPER – https://www.youtube.com/c/IdiotDeveloper/?sub_confirmation=1

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I am an independent researcher in the field of Artificial Intelligence. I love to write about the technology I am working on.

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