Character generation

this ppt in most useful for engineering students...

1. Character Generation Techniques Computer Graphics

2. Characters Generation in CG In computer graphics character can be generated using software. In hardware implementation of character generation limited faces of character can be generated. A wide variety of faces of character can be generated with software implementation. There are three methods for generating characters using software implementation. Stroke method Vector method or bitmap method. Star bust method

3. Stoke method • • • In this method we use a sequence of line drawing function and arc functions to generate characters. We can generate a sequence of character by assigning starting and end point of line or arc. By using this method various faces of character can be generated by changing the values (parameters) in line and arc function.

4. Stoke method • The main disadvantage of this method is when we draw a diagonal line it produce aliased character.

5. Bitmap Method

6. Program For Bitmap Method #include<stdio.h> #include<conio.h> #include<graphics.h> main() { int gd,gm,i,j; { 0, 0, 0, 0, 1, 0, 0, 0, 0}, { 0, 0, 0, 1, 0, 1, 0, 0, 0}, { 0, 0, 1, 0, 0, 0, 1, 0, 0}, { 0, 1, 0, 0, 0, 0, 0, 1, 0}, { 0, 1, 0, 0, 0, 0, 0, 1, 0}, { 0, 1, 0, 0, 0, 0, 0, 1, 0}, { 0, 1, 1, 1, 1, 1, 1, 1, 0}, { 0, 1, 0, 0, 0, 0, 0, 1, 0}, { 0, 1, 0, 0, 0, 0, 0, 1, 0}, { 0, 1, 0, 0, 0, 0, 0, 1, 0}, { 0, 1, 0, 0, 0, 0, 0, 1, 0}, { 0, 1, 0, 0, 0, 0, 0, 1, 0}, { 0, 1, 0, 0, 0, 0, 0, 1, 0}, int a[13][9] = { • • • • • • • • • • • • • • } ; /* Initialise graphics mode */ detectgraph(&gd,&gm); initgraph(&gd,&gm,"c:\\tc\\bgi"); • • • • for(i=0;i<13;i++) { for(j=0;j<9;j++) { putpixel(200+j,200+i,15*a[i][j]); } } getch(); c l o s e g r a ph ( ) ; }

7. Bitmap Method This method is suitable for producing various character. Font size of character can be increased by increasing the size of array. The main draw back of this method is this method produce aliased character.

8. Starbust Method In this method a fixed pattern of line is used to generate the character. In this method we use a combination of 24 bit line segment. In 24 bit line segment code each bit represent a single line. To highlight a line we put corresponding bit 1 in 24 bit line segment code and otherwise.

9. Starbust Method Disadvantages of starbust method 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 24 bit line segment code Here in this method 24 bit segment code is required to put in memory for generating character. Hence extra memory is required in this method. Character quality is poor due to limited face.

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