imagesize() function in C

The header file graphics.h contains imagesize() function which returns the number of bytes required to store a bit-image.
Syntax :

unsigned int imagesize(int left, int top,
                    int right, int bottom);

where,
left, top, right, and bottom
define the area of the screen 
in which image is stored.

Below is the implementation of imagesize() function.

// C Implementation for imagesize()
#include <graphics.h>
#include <stdio.h>

// driver code
int main()
{
    // gm is Graphics mode which is
    // a computer display mode that
    // generates image using pixels.
    // DETECT is a macro defined in
    // "graphics.h" header file
    int gd = DETECT, gm, color, bytes;
    char arr[100];

    // initgraph initializes the
    // graphics system by loading a
    // graphics driver from disk
    initgraph(&gd, &gm, "");

    // Draws a circle with center at
    // (200, 200) and radius as 50.
    circle(200, 200, 50);

    // draws a line with 2 points
    line(150, 200, 250, 200);

    // draws a line with 2 points
    line(200, 150, 200, 250);

    // imagesize function
    bytes = imagesize(150, 150, 250, 250);

    // sprintf stands for “String print”.
    // Instead of printing on console,
    // it store output on char buffer
    // which are specified in sprintf
    sprintf(arr, "Number of bytes required "
         "to store required area = %d", bytes);

    // outtext function displays text
    // at current position.
    outtextxy(20, 280, arr);

    getch();

    // closegraph function closes the
    // graphics mode and deallocates
    // all memory allocated by
    // graphics system .
    closegraph();

    return 0;
}

Output :