AI Course
Lesson 82: Image Processing Basics
Image processing is the foundation of computer vision. Before a model can recognize objects or understand scenes, images must often be cleaned, enhanced, or transformed.
These operations improve image quality and make important features easier for algorithms to detect.
Real-World Connection
Camera apps enhance photos automatically, medical scans are clarified for doctors, and security footage is improved for visibility. All of this uses image processing.
Even before deep learning models are applied, image processing prepares data for better results.
What Is Image Processing?
Image processing involves manipulating images to improve visual quality or extract useful information. It works directly on pixel values.
- Noise reduction
- Contrast enhancement
- Edge detection
- Geometric transformations
Reading and Displaying an Image
Let’s start with loading and displaying an image using OpenCV.
import cv2
image = cv2.imread("image.jpg")
cv2.imshow("Original Image", image)
cv2.waitKey(0)
cv2.destroyAllWindows()
This code reads an image from disk and displays it in a window.
Grayscale Conversion
Color images contain three channels (RGB). Converting to grayscale simplifies processing and reduces computation.
gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
cv2.imshow("Grayscale Image", gray)
cv2.waitKey(0)
cv2.destroyAllWindows()
Why Grayscale Is Useful
Many algorithms focus on intensity changes rather than color. Grayscale images highlight structure, edges, and shapes more clearly.
Image Resizing
Images often need to be resized for faster processing or model input requirements.
resized = cv2.resize(image, (300, 300))
cv2.imshow("Resized Image", resized)
cv2.waitKey(0)
cv2.destroyAllWindows()
Understanding Pixel Values
Each pixel has an intensity value. In grayscale images, values range from 0 (black) to 255 (white).
Image processing modifies these values mathematically to achieve desired effects.
Common Image Processing Operations
- Blurring to remove noise
- Thresholding to separate objects
- Sharpening to enhance edges
Practice Questions
Practice 1: What is the main goal of image processing?
Practice 2: Which image format reduces color information?
Practice 3: What does image processing operate on directly?
Quick Quiz
Quiz 1: Which task improves image quality?
Quiz 2: Why is grayscale conversion used?
Quiz 3: Which operation changes image dimensions?
Coming up next: Filters & Edge Detection — how machines detect boundaries and important structures in images.