Thursday, January 30, 2025

what is a pixel

 one should understand that, image is nothing but, an array or a matrix of multiple pixels which are properly arranged in columns and rows.    

Now, it is also good to understand what a pixel is. A pixel is a word framed from picture element.

"A pixel is the smallest unit in a digital images. Multiple pixels arranged in rows and columns actually from an image. An image is fully composed of pixels."

Monday, January 27, 2025

What is Image Processing?

 Assume a human seeing the above signage on the roads. Immediately, his/her eyes will start capturing the content and brain shall interpret what the signals signify. Based on the understanding, one would make a move further.

In digital image processing, the same image shall be fed in as an input to the system and the system  shall interpret and understand the content to let the further actions happends.

the algorithms developed shall play a major role in understanding the content with higher accuracy.

"Optical image processing is an area that deals with the object, optics and how processes are applied to an image that is available in the form  of reflected or transmitted."

"Analog image processing is an area that deals with the processing of analog electrical signals using analog circuits. The Imaging systems that use film for recording images are also knows as analog imaging systems.

Image Processing intro

Introduction-
  • Image speaks louder than words.
Researchers have been consistently working on developing image processing techniques which shall provide more features and better accuracy with increased speed of processing the image.

What is an Image?
Ans -
             "An image, be it a digital or a still image, all of it is nothing but a binary representation of some visual information."
  • The visual information can be a simple drawing, photographed pictures , and recorded graphs, logos of the organizations or anything of this sort. All these digital images have something in common.
  • they all can be stored and saved for future use electronically in any storage device.
  • Listeners are presented with a sample image with information inside it. This Image is a traffic sign, which gives information about the signals and signage for the riders.
  • This is a digital image and can be stored in any digital storage medium. To be more precise, this image is short which a digital camera.

Friday, November 29, 2024

Raster scan Vs Vector Scan

1. Raster Scan Display 

How It Works: A raster scan display works by painting an image on the screen pixel by pixel, row by row. It follows a systematic pattern where the electron beam (in CRT monitors) or the display elements (in modern LCD/LED screens) sweep across the screen from left to right, top to bottom, in a series of horizontal lines (scan lines). This process is akin to how a traditional TV screen works. 

Process: The display draws the image starting from the top-left corner, moving to the right, then moves to the next row below, and repeats this process until the entire screen is filled. This pattern creates a grid of pixels, where each pixel can have a color and brightness level. 

Characteristics:

    • Pixel-based: The screen consists of a grid of pixels, and each pixel can have a distinct color and intensity.
    • Continuous Image: Raster scan displays are capable of displaying detailed and complex images, including photographs and videos, because they break the image down into thousands (or millions) of tiny pixels.
    • Resolution: The resolution is determined by the number of pixels in the screen, often expressed as width × height (e.g., 1920 × 1080 for full HD).
  • Examples:

    • CRT monitors (older TVs and computer monitors)
    • LCD, LED, and OLED displays (modern screens)
    • Computer displays, television screens, digital photography, etc.
  • Advantages:

    • Can display full-color images, detailed graphics, and videos.
    • Suitable for complex images like photographs, movies, and web pages.
  • Disadvantages:

    • Requires a lot of memory to store the pixel data.
    • Image resolution is fixed by the number of pixels on the screen.

2. Vector Scan Display

  • How It Works: A vector scan display, also known as a calligraphic display, uses an electron beam to directly draw lines between specified points on the screen. Instead of filling in pixels across the screen, the beam moves to specific locations to draw the image by tracing out lines. It doesn't create images by filling pixels; rather, it traces out geometric shapes (such as lines, curves, and polygons) one at a time.

  • Process: The image is drawn by directly moving the electron beam to the endpoints of each line or curve, creating lines that connect these points. Once a line is drawn, the beam moves to the next point to draw the next line. The process is done sequentially for all the lines that make up the image.

  • Characteristics:

    • Line-based: The display creates an image using only lines and geometric shapes.
    • No pixel grid: It doesn't rely on a fixed grid of pixels to create the image, but rather draws lines directly between points.
    • Resolution: The resolution depends on the precision of the vector drawing system, not the number of pixels. The image can appear very smooth for simple shapes, but is less suited for complex or highly detailed images.
  • Examples:

  • Advantages:

    • Can display precise lines and curves without the need for a pixel grid.
    • More efficient for displaying simple geometric shapes like lines, curves, and text.
    • Requires less memory compared to raster displays, as only the endpoints of lines need to be stored.
  • Disadvantages:

    • Not suitable for displaying detailed, continuous-tone images (such as photographs) because it lacks a pixel-based grid.
    • More limited in terms of image complexity—vector displays are better for wireframe images and simple graphics, but not for detailed or realistic images.

is computer graphics played an important role in our life ? discuss

Yes, computer graphics play a crucial role in our everyday lives, and their impact is widespread across various industries and aspects of modern society. From entertainment to healthcare, education, and business, computer graphics are integral to many aspects of our personal and professional experiences. Here's a detailed look at why computer graphics are so important:

 1. Education and Training: Computer-generated model of the physical, financial and economic system is often used as educational aids. Model of physical systems, physiological system, population trends or equipment can help trainees to understand the operation of the system. 

 For some training applications, particular systems are designed. For example Flight Simulator. 

 Flight Simulator: It helps in giving training to the pilots of airplanes. These pilots spend much of their training not in a real aircraft but on the ground at the controls of a Flight Simulator.

 Advantages: 

 1. Fuel Saving 

 2. Safety 

 3. Ability to familiarize the training with a large number of the world's airports. 

 2. Use in Biology: Molecular biologist can display a picture of molecules and gain insight into their structure with the help of computer graphics. 

 3. Computer-Generated Maps: Town planners and transportation engineers can use computer-generated maps which display data useful to them in their planning work. 

 4. Architect: Architect can explore an alternative solution to design problems at an interactive graphics terminal. In this way, they can test many more solutions that would not be possible without the computer. 

 5. Presentation Graphics: Example of presentation Graphics are bar charts, line graphs, pie charts and other displays showing relationships between multiple parameters. Presentation Graphics is commonly used to summarize o Financial Reports o Statistical Reports o Mathematical Reports o Scientific Reports o Economic Data for research reports o Managerial Reports o Consumer Information Bulletins o And other types of reports 

 6. Computer Art: Computer Graphics are also used in the field of commercial arts. It is used to generate television and advertising commercial. 

 7. Entertainment: Computer Graphics are now commonly used in making motion pictures, music videos and television shows. 

 8. Visualization: It is used for visualization of scientists, engineers, medical personnel, business analysts for the study of a large amount of information. 

 9. Educational Software: Computer Graphics is used in the development of educational software for making computer-aided instruction. 

 10. Printing Technology: Computer Graphics is used for printing technology and textile design.

Wednesday, November 20, 2024

What is a Process?

A process is an independent unit of execution within an operating system. It represents a program or application that is being executed by the CPU.

Process States

1. Running: Process is currently executing.
2. Waiting: Process is waiting for resources or events.
3. Sleeping: Process is suspended, waiting for events.
4. Zombie: Process has terminated, but parent process hasn't acknowledged.
5. Dead: Process has terminated and been removed.


Process Types

1. Foreground Process: Interactive process with user input.
2. Background Process: Non-interactive process running without user input.
3. System Process: Operating system process, such as device drivers.
4. Daemon Process: Background process that runs continuously.

Process Creation

1. Fork: Creates a new process by duplicating an existing one.
2. Exec: Replaces the current process image with a new one.
3. CreateProcess: Windows API function to create a new process.

Process Termination

1. Exit: Process terminates normally, returning an exit code.
2. Kill: Process is forcibly terminated by the operating system.
3. Signal: Process receives a signal, which can terminate or interrupt it.

Creating Threads


1. Thread Class: Use the System.Threading.Thread class to create threads.

2. Thread Constructor: Pass a ThreadStart delegate or a ParameterizedThreadStart delegate to the constructor.

3. ThreadStart Delegate: Represents the method to be executed by the thread.


Example:


using System.Threading;


class Program

{

    static void Main()

    {

        Thread thread = new Thread(new ThreadStart(MyMethod));

        thread.Start();

    }


    static void MyMethod()

    {

        Console.WriteLine("Thread is running.");

    }

}


Processes-

1. Independent units of execution

2. Own memory space (virtual address space)

3. Created by operating system

4. Communicate through Inter-Process Communication (IPC) mechanisms


Threads

1. Lightweight processes
2. Share memory space with parent process
3. Created by process
4. Execute concurrently with other threads

Key Differences

1. Memory: Processes have separate memory, threads share memory
2. Creation: Processes created by OS, threads created by process
3. Communication: Processes use IPC, threads share memory
4. Resources: Processes have own resources, threads share resources


Thread Types

1. User-Level Threads (ULT)
2. Kernel-Level Threads (KLT)
3. Hybrid Threads



Process Communication

1. Pipes
2. Sockets
3. Shared Memory
4. Message Queues


Process Scheduling

1. First-Come-First-Served (FCFS)
2. Shortest Job First (SJF)
3. Priority Scheduling
4. Round Robin (RR)
5. Multi-Level Feedback Queue (MLFQ)


Thread Scheduling

1. Preemptive Scheduling
2. Non-Preemptive Scheduling
3. Time-Slicing

✅ UNIT 4 — POSET, LATTICES & BOOLEAN ALGEBRA (DISCRETE MATHEMATICS)

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