Digital image processing involves three main steps: 1) Image acquisition where light reflected off an object is captured by a camera sensor and converted to a digital image composed of pixels; 2) A digital image is a 2D representation of the image as a function of spatial coordinates and pixel intensity; 3) A simple model of image formation involves light reflecting off an object and being captured by the camera sensor.

1. Digital Image processing:
Image Acquisition
From:
Dr Shailendra Kumar
Department of ECE,
Integral University, Lucknow, U.P., India.

2. Light ?
• The visible area of the electromagnetic (EM) spectrum.
• It occurs between wavelengths of approximately 400 and 700
nanometers.

3. Digital Image Acquisition
Camera sensor captured the reflected light from object convert it into
analog signal and mapped into digital image. Smallest element of image is
called picture element or pixel.
Images taken from Gonzalez & Woods, Digital Image Processing (2002)

4. Digital Image: 2D representation
f (xm, yn)
y
x
An Image shown in figure is a 2D function, f(x, y)
where x and y are the coordinates &
Amplitude of f is called the gray level or intensity

5. A Simple model of image formation
• The light falls on the object.
• The light moves towards camera from object.
• The reflected light (from an object) captures by the
sensors of camera.
Source
Camera Sensor
Object

6. Thank You