Chapter 10 Digital Image Capture

What is interpolation?

A mathematical technique used to increase the apparent resolution of an image.

charge coupled device

An array of light sensitive sold state receptors that react electronically when exposed to light. Used most often in desktop scanners.

resolution

An image's sharpness or clarity; the number of pixels per unit of linear measurement on a video display or the number of dots per inch (DPI) in printed form.

________ are used to apply special effects to bitmap images.

Filters

photomultiplier tube (PMT)

Light sensitive tubes composed of highly sensitive photocells that transform variations in light into electric currents. The photocells create the input signals to the computing circuits in electronic scanners.

________ are used to isolate an area to protect it from change when applying color changes or special effects to the rest of the image.

Masks

interpolation

Mathematical technique used to increase that apparent resolution of an image. Increases image resolution buy adding data in intermediate shades of gray or color to surrounding areas.

digital form

Method used to represent information in a computer system. The info is stored and processed in binary form, as a series of on and off (the presence or absence of an electrial charge) states. The numerals 1 and 0 are conventionally used to represent the on and off states.

bit depth

Number of bits used to represent each pixel. Also known as tonal resolution.

When scanning text, you must use a(n) system to translate the bitmapped image into ASCII characters.

OCR

Drum scanners use _________ for gathering color information.

PMTs

What advantage do PCMCIA cards offer photographers using digital cameras?

Quick downloading of images without tying up the host camera.

What is spatial resolution? Tonal resolution?

Refers to the capability of a digital imaging device to address data in two dimensions - horizontally and vertically. This, or bit depth, is the number of bits of color or grayscale information that can be recorded per pixel.

Three main categories of digital cameras and camera backs.

Studio, field, point and shoot.

spatial resolution

The capability of a digital imaging device to address data in two dimensions - horizontal and vertical.

dynamic range

The gradations from light to dark that a digital imaging device can read or produce.

What is unsharp masking? (USM)

The increase of tonal contrast where light and dark tones come together as the edges of an image.

tonal resolution

The number of bits of color or grayscale information that can be recorded per pixel. Also known as bit depth.

analog form

The principle feature of something in this form is that it is continuous

The colors and lines of an image in _____ form are continuous. The colors and lines of an image in ______ form consist of values measured at distinct points.

analog and digital

CCD sensors are _____ and require special filters to separate the RGB light reflected by an object.

monochromatic