Graphics Devices and Display Systems Questions and Answers

Answer: C

Haptic technology provides tactile feedback, which is feedback through the sense of touch, for example vibrations, force or pressure felt by the user on a touchscreen, a game controller or a glove. 'Olfactory' belongs to the sense of smell and 'visual' to sight, so neither describes haptic feedback. 'Innovative' is a general word and does not name a kind of feedback. In practice haptic feedback is what a phone's vibration or a game controller's rumble provides, which is all felt through the skin.

Answer: B

A gyroscope detects orientation and angular velocity. It is what lets a phone or controller know how it has been turned and how fast. A light pen is a pointing device used on a CRT screen, a magnetometer measures the strength and direction of a magnetic field, as in a compass, and a proximity sensor detects nearby objects without touching them, so none of them measures angular velocity. Phones and game controllers use gyroscopes to sense rotation, which lets a game respond when the device is turned.

Answer: A

The CRT is the part that does the actual display in a computer: the cathode ray tube is the screen on which the picture is formed. VRAM is memory that holds the image data for the screen, and a GPU is the processor that calculates the graphics, so these two prepare the picture but do not show it. DPU is not a standard display device in the options and so cannot be the part that displays. The picture on a CRT is formed by an electron beam that strikes a phosphor-coated screen, which lights up where it is hit.

Answer: B

This ratio is the aspect ratio.

In computer graphics the aspect ratio of a display is the ratio of vertical points to horizontal points needed to produce lines of equal length in both directions. With an aspect ratio of 1 the pixels are square, so a line of n pixels is the same length horizontally and vertically; otherwise drawing must correct for it.

'Frame ratio', 'scanline ratio' and 'display ratio' are not the standard terms for this quantity.

Answer: D

Aliasing occurs when a continuous signal is sampled in a discrete manner with a constant rate.

Sampling turns a continuous signal into discrete samples. If the sampling rate is less than twice the highest frequency in the signal (the Nyquist rate), high frequencies are misrepresented as lower ones. In graphics this appears as jagged edges (staircase lines) and moire patterns, because a continuous image is sampled at discrete pixel positions.

A discrete signal is already sampled, and sampling 'in a continuous manner' is not sampling at all, so the other three options do not describe the effect.

Answer: C

Key frame systems are specialized animation languages.

In computer animation the animator specifies key frames, the positions at important moments, and a key-frame system generates the in-between frames automatically by interpolating object positions and shapes between them. Such systems are therefore described as specialised animation languages for producing the in-betweens.

General graphics languages, modelling languages and fractal generation tools build or describe objects, but they are not specialised for generating in-between frames.

Answer: A

The option that is not a category of graphics standards is Basic graphics system.

The other three are real, named standards or specifications. Portable Network Graphics (PNG) is a lossless raster image format, published as the W3C and ISO/IEC 15948 standard. OpenGL is the cross-language programming interface for rendering 2D and 3D graphics, maintained by the Khronos Group. OpenRaster is an open file format for layered raster images, used by painting programs such as Krita and MyPaint. 'Basic graphics system' is a generic phrase and does not name any standard.

What could not be confirmed: no reference was found that splits graphics standards into categories under these headings, so the key is kept and the answer rests on this elimination. A candidate who knows GKS and PHIGS as the classic graphics-system standards should not read 'Basic graphics system' as one of them.

Answer: C

The 3D graphics package is AC3D.

AC3D is a three-dimensional modelling program used to build polygon models and export them to formats used in games, simulators and virtual worlds.

Paint is a simple two-dimensional bitmap drawing program. 'Dream viewer' (Dreamweaver) is a web page editor, and Lightroom is a photo management and editing application. None of them builds 3D models.

Answer: A

The min filter is an Order statistic filter.

Order statistic (rank) filters sort the pixel values in the neighbourhood and pick one by its rank. The median filter picks the middle value, the max filter the largest and the min filter the smallest (the 0th percentile). The min filter is useful for finding the darkest points and for removing salt (white) noise.

Averaging filters compute a mean rather than ranking values, and sharpening filters use derivatives to enhance edges. 'Noise reduction' describes a purpose that several filter families serve, not the class to which the min filter belongs.

Answer: A

Lossless compression does not eliminate psychovisual redundancy.

Removing psychovisual redundancy means discarding information the eye is insensitive to, typically by quantisation. That information cannot be recovered, so it is used only in lossy compression such as JPEG.

Coding redundancy (removed by variable-length codes such as Huffman coding) and interpixel redundancy (removed by run-length, predictive or LZW coding) can both be removed without losing any information, so lossless methods do eliminate them. 'Both B and C' is therefore wrong.