b). 256, 8 bits per pixel = 2^8 colours.
Widely accepted industry standard uses 3 bytes, or 24 bits, per pixel, with one byte for each primary color results in 256 different intensity levels for each primary color. Thus apixel can take on a color from 256 X 256 X 256 or 16.7 million possible choices. In Bi-level imagerepresentation one bit per pixel is used to represent black-and white images. In gray levelimage 8 bits per pixel to allow a total of 256 intensity or gray levels. Image representationusing lookup table can be viewed as a compromise between our desire to have a lower storage requirement and our need to support a reasonably sufficient number of simultaneous colors.
5. List and explain different text mode built-in functions of CProgramming language.
The different text mode built-in functions of C Programming language are listed below :-
i). textmode( int mode);
This function sets the number of rows and columns of the screen, mode variable can takethe values 0, 1, 1, or 3.0: represents 40 column black and white1: represents 40 column color 2: represents 80 column black and white3: represents 80 column color Example: textmode(2); // sets the screen to 80 column black and white
This function clears the entire screen and locates the cursor on the top left corner(1,1)Example clrscr(); // clears the screen
iii). gotoxy(int x, int y);
This function positions the cursor to the location specified by x and y. x represents the rownumber and y represents the column number.Example: gotoxy(10,20) // cursor is placed in 20th column of 10th row
iv). textbackground (int color);
This function changes the background color of the text mode. Valid colors for the CGA arefrom 0 to 6 namely BLACK, BLUE, GREEN, CYAN, RED, MAGENTA and BROWN.Example: textbackground(2); Or //changes background color to bluetextbackground(BLUE);
v). textcolor (int color);
This function sets the subsequent text color numbered between 0 to 15 and 128 for