BMP width & height, BinaryReader

Proposed exercise

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Create a C# program to display the width and the height of a BMP file, using a BinaryReader.

The structure of the header of a BMP file is:

TYPE OF INFORMATION	POSITIONINTHEFILE
File type (letters BM)	0-1
FileSize	2-5
Reserved	6-7
Reserved	8-9
Start of image data	10-13
Sizeofbitmapheader	14-17
Width (pixels)	18-21
Height (pixels)	22-25
Numberofplanes	26-27
Sizeofeachpoint	28-29
Compression(0=notcompressed)	30-33
Imagesize	34-37
Horizontal resolution	38-41
Verticalresolution	42-45
Sizeofcolortable	46-49
Importantcolorscounter	50-53

Output

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Solution

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using System;
using System.IO;

public class BmpMesures
{
public static void Main() 
{    
byte b1, b2;
int width, height;

BinaryReader file = 
new BinaryReader( File.Open("test.bmp", FileMode.Open));

b1 = file.ReadByte();
b2 = file.ReadByte();

if (b1 == 0x42 && b2 == 0x4D)  
{
file.BaseStream.Seek(18, SeekOrigin.Begin);

width = file.ReadInt32();
height = file.ReadInt32();

Console.WriteLine("Width is of {0} pixels", width);
Console.WriteLine("Height is of {0} pixels", height);
}
else
Console.WriteLine("It not .BMP");

file.Close();
}
}