Graphics Devices and Display Systems Questions and Answers

Answer: D

The number of distinct binary images of size \(M \times N\) is \(2^{MN}\), which is option (D). There are \(M \times N\) pixels and each can take either of two values, so there are \(2 \times 2 \times \cdots\) (MN times) possible images.

\(M + N\) and \(M \times N\) count the rows and columns or the pixels and not the images, and \(2^{M + N}\) would be the answer if only the rows and columns could be chosen independently.

Answer: A

If f(x, y) is a digital image, then x, y and the amplitude values of f are all finite. A digital image is a sampled and quantised version of a scene: the coordinates are discrete and limited in number and the amplitude takes only a limited number of grey levels. The answer is (A).

It is only in an analog image that the coordinates and the amplitude vary continuously through an infinite set of values, so (B) is wrong.

Answer: D

In MPEG, spatial compression is like JPEG, and temporal compression removes redundant frames: it uses the fact that successive frames of video are almost the same, so the repeated information is dropped.

The words temporal and spatial describe kinds of compression, not frames to be removed, and voice frames are not the subject here. So redundant is the word that completes the sentence.

Answer: D

The key marks all four devices, so the answer is (i), (ii), (iii) and (iv). Alphanumeric devices such as the keyboard, thumb wheels, digitizers and joysticks are interactive input devices, in which the user acts on the device to supply input.

The options that list only some of these leave out devices the key counts as active, and so are incomplete.

Answer: A

The fundamental methods of antialiasing are increasing the sample rate and treating a pixel as a finite area rather than as a point. Both reduce the jagged edges: more samples capture finer detail, and area sampling averages the intensity over the pixel.

Decreasing the sample rate makes aliasing worse, so statement (iii) is wrong, and the options containing it are wrong. The options that give only (i) or only (ii) are incomplete.

Answer: A

HSV stands for Hue, Saturation, Value and HLS for Hue, Lightness, Saturation. They are two colour models based on perceptual attributes of colour.

The other options invent expansions such as High, Standard or Highly Saturated, which are not the names of the components. So only the first option names the models correctly.

Answer: C

Only statement III is not true.

Beam-penetration is used with random-scan monitors and the shadow-mask method is used with raster-scan systems, so statements I and II are true. The shadow-mask method produces a much wider range of colours and better pictures than beam-penetration, which gives only four or so colours, so statement IV is true and statement III, which says the opposite, is false.

Option A would make the true statements I and II the untrue ones, option B includes the true statement II, and option D picks the true statement IV.

Answer: D

The line caps are butt cap, round cap and projecting square cap.

A butt cap is cut square at the end points of the line, a round cap adds a semicircle at each end, and a projecting square cap extends the line by half its width and squares it off.

'Sharp cap' is not a standard line cap in the usual list. Options A and C include it, and option B leaves out the projecting square cap, so only option D gives the complete standard set.

Answer: C

The match is a-iv, b-iii, c-ii, d-i.

A line has the attributes type, width and colour (iv). A fill area has style, colour and pattern (iii). Text has colour, size and font (ii). A marker has type, size and colour (i).

Code (C) gives these four pairs. The other codes give a line the marker attributes of size or the text attribute of font, which a line does not have.

Answer: D

RGB and CMY are defined with three primary colours.

The RGB model uses red, green and blue as its three primaries and the CMY model uses cyan, magenta and yellow. Both are therefore defined by three primary colours.

HSV and HLS describe colour by hue, saturation and value or lightness, which are perceptual attributes and not three primary colours, so options A, B and C that include them are wrong.