Exercise
Display BPM on console
Objetive
The Netpbm format is a family of image file formats designed with simplicity in mind, rather than small size. They can represent color, grayscale, or black and white images using plain text (even though a binary variant exists).
For example, a black and white image coded in ASCII is represented using the header "P1".
The following line (optional) might be a comment, preceded with #.
The next line contains the width and height of the image.
The remaining line(s) contain the data: 1 for black points and 0 for white points, as in this example:
P1
This is an example bitmap of the letter "J"
6 10
0 0 0 0 1 0
0 0 0 0 1 0
0 0 0 0 1 0
0 0 0 0 1 0
0 0 0 0 1 0
0 0 0 0 1 0
1 0 0 0 1 0
0 1 1 1 0 0
0 0 0 0 0 0
0 0 0 0 0 0
(that would be the content of a file named "j.pbm").
Create a program to decode an image file like this and display it on the screen using only the console. Remember that the comment is optional.
Example Code
// Import the System namespace for basic input/output operations
using System;
// Import the System.IO namespace for file operations
using System.IO;
// Declare the main Program class
class Program
{
// Main method where the program starts
static void Main()
{
// Specify the path to the PBM image file
string filePath = "j.pbm"; // Replace this with the path to your PBM file
// Try to read and display the PBM file content
try
{
// Open the file using StreamReader to read text from the PBM file
using (StreamReader reader = new StreamReader(filePath))
{
// Read the first line, which should be "P1" (PBM header)
string header = reader.ReadLine();
if (header != "P1") // Check if the header is "P1"
{
Console.WriteLine("Invalid PBM format. Expected 'P1'.");
return; // Exit the program if the header is not correct
}
// Read the optional comment line (skip it)
string commentLine = reader.ReadLine();
while (commentLine.StartsWith("#")) // Check if the line starts with "#"
{
commentLine = reader.ReadLine(); // Read the next line if it's a comment
}
// Read the width and height of the image
string[] dimensions = commentLine.Split(' '); // Split the dimensions by space
int width = int.Parse(dimensions[0]); // First element is the width
int height = int.Parse(dimensions[1]); // Second element is the height
// Print a message to inform the user about the image size
Console.WriteLine($"Image dimensions: {width} x {height}");
// Loop through each row of pixels and print it to the console
for (int y = 0; y < height; y++) // Loop through each row
{
// Read the next line, which contains the pixel data for the row
string row = reader.ReadLine();
string[] pixels = row.Split(' '); // Split the row into individual pixel values
// Loop through each pixel in the row
for (int x = 0; x < width; x++) // Loop through each pixel in the row
{
// Check the pixel value: 0 means white, 1 means black
if (pixels[x] == "1")
{
Console.Write("X"); // Display 'X' for black pixels
}
else
{
Console.Write(" "); // Display a space for white pixels
}
}
Console.WriteLine(); // Move to the next line after printing the row
}
}
}
catch (Exception ex) // Catch any errors that may occur during file reading
{
// Print the error message to the console
Console.WriteLine($"Error reading the file: {ex.Message}");
}
}
}