by Dinesh Thakur

On the Macintosh, some programs let you edit bitmapped graphics as FatBits. In FatBits mode, the individual dots, or pixels, making up the image are blown up so you can work with them easily, one at a time. If you see stray dots in an image you've scanned, or if a line in a picture is just slightly too thick or too skinny, it's almost impossible to make precise changes working at normal size.

 
by Dinesh Thakur

A typical black-and-white photograph uses only one color. In a duotone, though, the black-and-white photograph (or other artwork) is reproduced using two colors. Perhaps it's black and brown, or black and grey, or dark grey and a rusty color. Halftone images are generated for the photograph, one slightly underexposed and one slightly overexposed, and the two are printed one on top of the other. The result can be an incredibly rich, powerful image-much richer and more interesting than the image with one color. The artist/designer has control over the values and percentages of the two different colors. It is also possible to make "tritones" using three different colors, and "quadtones," using four different colors.

 
by Dinesh Thakur

Whenever a photograph, painting or drawing containing many colors or gray tones is printed, the colors and tones must be simulated with tiny dots. Dot gain refers to an increase in the size of these dots when they are actually printed on the paper by the printing press. The dots can increase in size rather dramatically once the ink hits the paper, depending on the characteristics of the press, the absorbency of the paper, and the nature of the ink that is used.

 
by Dinesh Thakur

When text or a graphic image is displayed on amonitor,or screen, the smoothness of the edges is limited by the resolution of the screen, which means the edges tend to be a little jagged. This jaggedness is also called aliasing.

 
by Dinesh Thakur

A mathematical point (x, y) where x and y are real numbers within an image area, needs to be scan converted to a pixel at location (x’, y’). This may be done by making x’ to be the integer part of x, and y’ to be the integer part of y. In other words, x’ = floor(x) and y’ = floor(y),

 
by Dinesh Thakur

You know that a line in computer graphics typically refers to a line segment, which is a portion of a straight line that extends indefinitely in opposite directions. You can define a line by its two end points and by the line equation y = mx + c, where m is called the slope and c the y intercept of the line. Let the two end points of a line be P1(x1, y1) and P2(x2, y2). The line equation describes the coordinates of all the points that lie between the two endpoints.



 
by Dinesh Thakur

DDA algorithm is an incremental scan conversion method. Here we perform calculations at each step using the results from the preceding step. The characteristic of the DDA algorithm is to take unit steps along one coordinate and compute the corresponding values along the other coordinate. The unit steps are always along the coordinate of greatest change, e.g. if dx = 10 and dy = 5, then we would take unit steps along x and compute the steps along y.

 
by Dinesh Thakur

You know that DDA algorithm is an incremental scan conversion method which performs calculations at each step using the results from the preceding step. Here we are going to discover an accurate and efficient raster line generating algorithm, the Bresenham's line-drawing algorithm.