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What is Image Processing?

What is Image Processing?

Not only does image processing involve pixels, but it also plays a major role in transforming our perception, comprehension, and interaction with our ever-changing reality. In this blog, we will learn about what image processing is, its techniques, and the role of machine learning in image processing, along with its application and scope.

Table of Contents

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Definition of Image Processing

Image processing is a field of study and technology that involves the manipulation of visual information contained in images. It includes a wide range of approaches and strategies intended to improve, examine, or otherwise work with images for different objectives. Image processing is widely utilized in many different domains, including computer vision, multimedia, medical imaging, and remote sensing. It can be used for digital or analog images.

Extracting useful information from images, enhancing image quality, or carrying out certain operations like pattern identification, object detection, image segmentation, and image restoration are the objectives of image processing. To accomplish the intended outcomes, a number of procedures, such as filtering, processing, and analysis, are applied to the images. From facial identification and the entertainment industry to medical diagnostics and satellite imagery analysis, image processing is essential in many applications.

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Techniques of Image Processing

There are various techniques used in image processing to manipulate and analyze images for different purposes. Here are some common techniques:

Image Enhancement

Image Enhancement

Enhancing an image is the process of making it look better. There are numerous ways to accomplish this, including:

  • Contrast Adjustment: This involves altering an image’s brightness and contrast to enhance the visibility of its features.
  • Noise Reduction: Removing noise from an image, such as grain or speckles, is known as noise reduction.
  • Sharpening: Enhancing the sharpness of an image’s edges is known as sharpening.
  • Filtering: Applying a filter to an image to either enhance or remove specific aspects is known as filtering.

Image Segmentation 

Image Segmentation 

The technique of splitting an image into distinct areas or objects is known as picture segmentation. There are numerous ways to accomplish this, including:

  • Region-Based Segmentation: Pixels are grouped into regions according to how similar they are in a process known as region-based segmentation.
  • Thresholding: Setting a threshold is the first step in turning a picture into a binary image.
  • Edge Detection: Edge detection is the process of locating an object’s edges within a picture.

Image Representation and Description

Image Representation and Description

The process of representing an image in a way that facilitates analysis and recognition is known as image representation and description. There are numerous ways to accomplish this, including:

  • Moment Invariants: Features of a picture that remain constant in terms of translation, rotation, and scale are known as moment invariants.
  • Fourier Descriptors: Fourier descriptors are characteristics of an image derived from its Fourier transformation.
  • Zernike Moments: Moments that are invariant to rotation are known as Zernike moments.

Image Classification and Recognition

Image Classification and Recognition

The process of recognizing and categorizing items in a picture is known as image classification and recognition. There are several ways to accomplish this, including:

  • Support Vector Machines: Support vector machines are a kind of machine learning technique that is frequently applied to the recognition and categorization of images.
  • Neural Networks: A class of machine learning algorithms called neural networks draws inspiration from the structure and operations of the human brain.
  • Template Matching: This technique looks for matches between an image and a template.

Image Compression

Image Compression

The process of shrinking an image file’s size without noticeably sacrificing its quality is known as image compression. There are numerous ways to accomplish this, including:

  • Lossless Compression: A compression that preserves all of the original image’s information is known as lossless compression.
  • Lossy Compression: Although some information from the original image is lost via this sort of compression, it is typically undetectable.

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How Does Machine Learning Help in Image Processing?

Machine learning plays a crucial role in image processing by providing powerful tools for automated analysis, recognition, and decision-making based on patterns and features extracted from images. In image processing, machine learning algorithms are trained on large datasets to learn patterns and relationships within the data. This enables them to generalize and make predictions or classifications on new, unseen images. In tasks such as image recognition, object detection, and segmentation, machine learning models, particularly deep learning models like convolutional neural networks (CNNs), have demonstrated remarkable accuracy. The integration of machine learning in image processing not only automates and speeds up analysis but also enables systems to adapt and improve over time as they encounter more diverse and complex image data. 

Libraries and Frameworks for Image Processing

There are several libraries and frameworks widely used in the field of image processing, providing developers and researchers with tools to efficiently work with images and implement various techniques. Here are some popular ones:

OpenCV

OpenCV is a popular open-source computer vision library that offers a full range of capabilities for processing images and videos. It is known for its effectiveness in real-time applications and supports a wide range of programming languages and platforms.

Here is a code for GreyScaling using OpenCV:

import cv2
import matplotlib.pyplot as plt
# Read an image
image = cv2.imread('/content/group-portrait-adorable-puppies.jpg')
# Convert the image to greyscale
gray_image = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
# Display the original and greyscale images
fig, axes = plt.subplots(1, 2, figsize=(10, 5))
axes[0].imshow(cv2.cvtColor(image, cv2.COLOR_BGR2RGB))
axes[0].set_title('Original Image')
axes[0].axis('off')
axes[1].imshow(gray_image, cmap='gray')
axes[1].set_title('Greyscale Image')
axes[1].axis('off')
plt.show()

Output:

TensorFlow

TensorFlow is an open-source machine learning library, and Keras is a high-level neural network API that runs on top of TensorFlow. They are frequently employed in deep learning image processing applications, including object recognition and picture categorization.

Given below is the TensorFlow code for image rotation:

import tensorflow as tf
import matplotlib.pyplot as plt
# Read an image
image_path = "/content/imgpsh_fullsize_anim.jpeg"
image = tf.io.read_file(image_path)
image = tf.image.decode_jpeg(image)
# Rotate the image
rotated_image = tf.image.rot90(image)
# Display the original and rotated images
fig, axes = plt.subplots(1, 2, figsize=(10, 5))
axes[0].imshow(image)
axes[0].set_title('Original Image')
axes[0].axis('off')
axes[1].imshow(rotated_image)
axes[1].set_title('Rotated Image')
axes[1].axis('off')
plt.show()

Output:

TensorFlow

Scikit-Image

Scikit-Image is a Python image processing set of algorithms. It provides a range of tools for tasks like filtering, segmentation, and feature extraction and builds upon NumPy and SciPy.

Below is the code for image compression using Sklearn:

import matplotlib.pyplot as plt
from skimage import io, color
from sklearn.cluster import KMeans
# Load an image
image_path = "/content/imgpsh_fullsize_anim.jpeg"
image = io.imread(image_path)
# Convert the image to RGB (if it's not already)
if image.shape[-1] == 4:  # Check if the image has an alpha channel
    image = color.rgba2rgb(image)
# Flatten the image into a 2D array of pixels
pixels = image.reshape((-1, 3))
# Define the number of clusters (colors) for compression
n_clusters = 16
# Apply KMeans clustering for quantization
kmeans = KMeans(n_clusters=n_clusters, random_state=42)
kmeans.fit(pixels)
# Replace each pixel with its cluster center
compressed_pixels = kmeans.cluster_centers_[kmeans.labels_].reshape(image.shape)
# Display the original and compressed images
fig, axes = plt.subplots(1, 2, figsize=(10, 5))
axes[0].imshow(image)
axes[0].set_title('Original Image')
axes[0].axis('off')
axes[1].imshow(compressed_pixels.astype('uint8'))
axes[1].set_title('Compressed Image')
axes[1].axis('off')
plt.show()

Output:

Scikit-Image

PyTorch

PyTorch is another popular deep-learning framework, particularly known for its dynamic computation graph that can be used for image-processing tasks. It is similar to TensorFlow, but it is known for its flexibility and ease of use. It is widely used in research and industry for image processing tasks, offering flexibility and ease of use.

The code snippet in PyTorch for making an image blur is as follows:

import cv2
import torch
import matplotlib.pyplot as plt
from torchvision import transforms
# Read an image
image_path = "/content/imgpsh_fullsize_anim.jpeg"
image = cv2.imread(image_path)
image = cv2.cvtColor(image, cv2.COLOR_BGR2RGB)
# Convert image to PyTorch tensor
transform = transforms.Compose([
    transforms.ToTensor(),
])
image_tensor = transform(image).unsqueeze(0)  # Add a batch dimension
# Convert tensor back to a numpy array for OpenCV manipulation
numpy_image = image_tensor.squeeze(0).permute(1, 2, 0).numpy()
# Convert the numpy array to BGR format for OpenCV
bgr_image = cv2.cvtColor(numpy_image, cv2.COLOR_RGB2BGR)
# Apply Gaussian blur using OpenCV
blurred_image = cv2.GaussianBlur(bgr_image, (21, 21), 0)
# Convert the blurred image back to RGB for display
blurred_image_rgb = cv2.cvtColor(blurred_image, cv2.COLOR_BGR2RGB)
# Display the original and blurred images
fig, axes = plt.subplots(1, 2, figsize=(10, 5))
axes[0].imshow(image)
axes[0].set_title('Original Image')
axes[0].axis('off')
axes[1].imshow(blurred_image_rgb)
axes[1].set_title('Blurred Image')
axes[1].axis('off')
plt.show()

Output: 

PyTorch

PIL

PIL (Python Imaging Library) is a comprehensive library for image processing in Python. It provides a set of modules and classes for opening, manipulating, and saving many different image file formats. Widely employed in various fields, PIL is essential for tasks such as image enhancement, transformation, and format conversion in both academic and industrial applications. With its user-friendly interface, PIL serves as a valuable resource for prototyping and implementing diverse image-processing algorithms within the Python ecosystem.

Here’s a practical implementation in PIL for resizing an image:

from PIL import Image
import matplotlib.pyplot as plt
# Open an image using PIL
image_path = "/content/imgpsh_fullsize_anim.jpeg"
image = Image.open(image_path)
# Define the desired width and height for resizing
width = 300
height = 200
# Resize the image
resized_image = image.resize((width, height))
# Display the original and resized images
fig, axes = plt.subplots(1, 2, figsize=(10, 5))
axes[0].imshow(image)
axes[0].set_title('Original Image')
axes[0].axis('off')
axes[1].imshow(resized_image)
axes[1].set_title('Resized Image')
axes[1].axis('off')
plt.show()

Output:

PIL

Applications of Image Processing

Image processing finds applications in a wide range of fields due to its ability to analyze, enhance, and interpret visual information. The following applications represent just a subset of the diverse uses of image processing technology, and ongoing research and advancements continue to expand their capabilities across various domains.

  • Medical Imaging: To improve the visualization, analysis, and diagnosis of medical disorders, image processing is frequently employed in medical imaging procedures like X-rays, CT scans, MRIs, and ultrasounds.
  • Computer Vision: In order for systems to recognize and track objects in real-time, image processing is crucial to computer vision applications. This is important for robots, surveillance, and driverless cars.
  • Biometrics: Facial recognition systems employ image processing for security and authentication, allowing entry to restricted areas or unlocking devices.
  • Remote sensing: Image processing is used to analyze satellite and aerial photos for urban planning, agriculture evaluation, disaster relief, and environmental monitoring.
  • Optical Character Recognition (OCR) and Document Analysis: In document analysis, image processing is used to extract text, identify characters, and turn scanned documents into editable text.
  • Forensic Analysis: To detect manipulation, fraud, or other changes, digital photos and videos are analyzed using image processing techniques in forensic investigations.
  • Entertainment and Multimedia: Photoshop and other image editing and manipulation programs depend on image processing. It is utilized in video processing for compression, enhancement, and special effects.

Scope of Image Processing 

Because of recent technological advancements and the growing need for advanced visual information processing across a range of industries, the field of image processing is quickly growing. Convolutional neural networks (CNNs) and deep learning have made enormous advances in recent years, revolutionizing image processing applications.

Developments in real-time image processing have become essential for applications like virtual reality (VR) and augmented reality (AR). The usage of these technologies in training simulations, education, gaming, and other industrial applications is growing. Creating immersive and interactive experiences heavily relies on the real-time processing and rendering of high-quality pictures.

When 5G, edge computing, and the Internet of Things (IoT) are combined, image processing will probably become even more widespread in the future. Smart cities, intelligent transportation systems, and industrial automation will be made possible by these breakthroughs, which will make it possible to handle massive amounts of picture and video data more efficiently in real-time. 

Image processing is anticipated to play a major role in the development of modern technologies like robotic vision, tailored medicine, and smart surveillance as the need for automated and intelligent visual analysis grows. Image processing is interdisciplinary and at the forefront of innovation, with the potential to touch many parts of our everyday lives and industries in the years to come. This is made possible by ongoing research in computer vision and machine learning.

Endnote

In a pixelated world, image processing emerges as the silent innovator. From revolutionizing healthcare diagnostics to crafting vivid augmented realities, its impact resonates across industries. As 5G, AI, and IoT converge, the future promises even grander transformations—smart cities, smooth transportation, and beyond. More than just pixels, image processing defines our visual future, pushing boundaries in personalized medicine and intelligent surveillance. It’s not just about processing images; it’s about shaping a tech-driven tomorrow where pixels pave the way for unprecedented possibilities.

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Senior Research Analyst

As a Senior Research Analyst, Arya Karn brings expertise in crafting compelling technical content in Data Science and Machine Learning. With extensive knowledge in AI/ML, NLP, DBMS, and Generative AI, his works get lakhs of views across social platforms that benefit both technical and business spheres.