Concept of Pixel in C Graphics

Concept of Pixel in C Graphics Wondering What a Pixel is!!!!!!!

            

Pixel is otherwise called as picture elements. These are nothing but small dots. Using these tiny dots or in other words pixels images especially graphics images are built on screen. 

If all pictures are built by concept of pixel then wondering how each picture differ that is how
some picture appear more brighter while some other have a shady effect. All this is by the
concept or technically terminology called as resolution.

So let’s have an insight on this important terminology.

Resolution is the number of rows that appear from top to bottom of a screen and in turn the
 number of pixels or pixel elements that appear from left to right on each scan line. Based on
 this resolution only the effect of picture appears on screen. In other words greater the
resolution
greater will be the clarity of picture. This is because greater the number of dots greater will
be sharpness of picture. That is resolution value is directly proportional to clarity of picture.

There are generally two modes available namely text and graphics. In a graphics mode we
have generally the following adapters namely CGA called as Color Graphics Adapter,
EGA and VGA. Each adapter differs in the way of generating colors and also in the number
of colors produced by each adapter. Pixel being a picture element when we consider the
graphics mode each pixel
 has a color associated with it. But the way these colors are used depends on adapters because
 each adapter differs in the way they handle colors and also in the number of colors supported.

Having known about adapters now let us start knowing on how to start switching to graphics
 mode from text mode in other words how to start using pixel and resolution concepts.

This is done by a function called intigraph ( ).This intigraph ( ) takes in it 2 main arguments as
input namely gd and gm.

In this gd has the number of mode which has the best resolution. This is very vital for graphics
 since the best resolution only gives a sharper picture as we have seen before. This value is
obtained by using the function called as getgraphmode ( ) in C graphics. The other argument
gm gives insight about the monitor used, the corresponding resolution of that, the colors that
are available since this varies based on adapters supported. This value is obtained by using
the function named as getmodename ( ) in C graphics.

Graphics function in C and Pixel concept in that

There are numerous graphics functions available in c. But let us see some to have an
understanding of how and where a pixel is placed in each when each of the graphics
function gets invoked.

Function:

putpixel(x, y, color) 

Purpose:

The functionality of this function is it put a pixel or in other words a dot at position x, y
given in inputted argument. Here one must understand that the whole screen is imagined
as a graph. In other words the pixel at the top left hand corner of the screen represents
the value (0, 0).

Here the color is the integer value associated with colors and when specified the picture
element or the dot is placed with the appropriate color associated with that integer value.

Function:

Line(x1, y1, x2, y2)

Purpose:

The functionality of this function is to draw a line from (x1,y1) to (x2,y2).Here also the
coordinates are passed taking the pixel (0,0) at the top left hand corner of the screen
as the origin. And also one must note that the line formed is by using number of pixels
placed near each other. 

Function:

getpixel(x, y)

Purpose:

This function when invoked gets the color of the pixel specified. The color got will be the
integer value associated with that color and hence the function gets an integer value as
return value.

So the smallest element on the graphics display screen is a pixel or a dot and the pixels
are used in this way to place images in graphics screen in C language.