Untitled Quiz

Environment and Bio-sensing

• Environment and bio-sensing are rapidly developing areas that involve sensors all around us, such as car courtesy lights, ultrasound detectors, RFID security tags, and temperature, weight, and location sensors.
• Our bodies also have sensors, such as iris scanners, body temperature, heart rate, galvanic skin response, and blink rate.

Printing and Scanning

Printing

• Printing involves making images from small dots, allowing for any character set or graphic to be printed.
• Critical features of printing include resolution, size and spacing of dots, and speed, which are usually measured in dots per inch (dpi) and pages per minute, respectively.
• Types of dot-based printers include dot-matrix, ink-jet, bubble-jet, and laser printers, which vary in resolution and cost.

Printing in the Workplace

• Shop tills often use dot-matrix printers, which can print on multiple paper rolls and may also print cheques.
• Thermal printers are simple and low-maintenance, but produce poor-quality prints and are often used in fax machines.

Fonts

• A font is a particular style of text, and its size is measured in points, with 1 point being approximately 1/72 of an inch.
• Fonts can be fixed-pitch, where every character has the same width, or variable-pitched, where characters have varying widths.
• Serif fonts have splayed ends, while sans-serif fonts have square-ended strokes.

Readability of Text

• Lowercase letters are easier to read, while uppercase letters are better suited for individual letters and non-words.
• Serif fonts are helpful for long lines of printed text, but sans-serif fonts are often better on screen.

Page Description Languages

• Pages can be converted into bitmaps and sent to printers, but this can be huge.
• Alternatively, page description languages like PostScript can be used, which send a description of the page and instructions for curves, lines, and text in different styles.

Screen and Page

• WYSIWYG (what you see is what you get) is the aim of word processing, but screens and print have different resolutions and orientations.
• Different designs and graphics are needed for screen and print.

Scanners

• Scanners take paper and convert it into a bitmap, with types including flat-bed and hand-held scanners.
• Scanners shine light at paper and note the intensity of reflection, capturing colour or greyscale images.
• Typical scanner resolutions range from 600-2400 dpi.

Scanners (ctd)

• Scanners are used in desktop publishing for incorporating photographs and other images.
• They are also used in document storage and retrieval systems, doing away with paper storage.

Extra Topics

Interaction Design, Design Paradigms

• In HCI, interaction design involves user modelling and design paradigms.

Technology

• Display technologies include plasma, video walls, projected, and back-projected displays.

Situated Displays

• Situated displays are public displays that show information relevant to the location.
• They can be interactive or display-only, and the location of the display matters.

Hermes

• Hermes is a situated display system consisting of small displays beside office doors.
• Handwritten notes are left using a stylus, and the office owner can read notes using a web interface.

Digital Paper

• Digital paper is a thin, flexible sheet that can be updated electronically, retaining its display.
• It is used in PDAs, portables, and notebooks, and increasingly on desktops and home TVs.

Special Displays

Random Scan

• Random scan displays draw lines to be displayed directly, with no jaggies.
• Lines need to be constantly redrawn, and this technology is rarely used except in special instruments.

Direct View Storage Tube (DVST)

• DVST displays are similar to random scan but persistent, with no flicker.
• They can be incrementally updated but not selectively erased, and are used in analogue storage oscilloscopes.

Large Displays

• Large displays are used for meetings, lectures, and other gatherings.