Reference

Last updated on 2023-12-18 | Edit this page

Glossary


(Some definitions are taken from Glosario. Follow the links from terms to see definitions in languages other than English.)

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adaptive thresholding
thresholding that uses a cut-off value that varies for pixels in different regions of the image.
additive colour model
a colour model that predicts the appearance of colours by summing the numeric representations of the component colours.
bacterial colony
a visible cluster of bacteria growing on the surface of or within a solid medium, presumably cultured from a single cell.
binary image
an image of pixels with only two possible values, 0 and 1. Typically, the two colours used for a binary image are black and white.
bit
a unit of information representing alternatives, yes/no, true/false. In computing a state of either 0 or 1.
blur
the averaging of pixel intensities within a neighbourhood. This has the effect of “softening” the features of the image, reducing noise and finer detail.
BMP (bitmap image file)
a raster graphics image file format used to store bitmap digital images, independently of the display device.
bounding box
the smallest enclosing box for a set of points.
byte
a unit of digital information that typically consists of eight binary digits, or bits.
colorimetrics
the processing and analysis of objects based on their colour.
compression
a class of data encoding methods that aims to reduce the size of a file while retaining some or all of the information it contains.
channel
a set of pixel intensities within an image that were measured in the same way e.g. at a given wavelength.
crop
the removal of unwanted outer areas from an image.
colour histogram
a representation of the number of pixels that have colours in each of a fixed list of colour ranges.
edge detection
a variety of methods that attempt to automatically identify the boundaries of objects within an image.
fixed-level thresholding
thresholding that uses a single, constant cut-off value for every pixel in the image.
grayscale
an image in which the value of each pixel is a single value representing only the amount of light (or intensity) of that pixel.
histogram
a graphical representation of the distribution of a set of numeric data, usually a vertical bar graph.
image segmentation
the process of dividing an image into multiple sections, to be processed or analysed independently.
intensity
the value measured at a given pixel in the image.
JPEG
a commonly used method of lossy compression for digital images, particularly for those images produced by digital photography
kernel
a matrix, usually relatively small, defining a neighbourhood of pixel intensities that will be considered during blurring, edge detection, and other operations.
left-hand coordinate system
a system of coordinates where the origin is at the top-left extreme of the image, and coordinates increase as you move down the y axis.
lossy compression
a class of data compression methods that uses inexact approximations and partial data discarding to represent the content.
lossless compression
a class of data compression methods that allows the original data to be perfectly reconstructed from the compressed data.
maize
a common crop plant grown in many regions of the world. Also known as corn.
mask
a binary matrix, usually of the same dimensions as the target image, representing which pixels should be included and excluded in further processing and analysis.
morphometrics
the processing and analysis of objects based on their size and shape.
noise
random variation of brightness or colour information in images. An undesirable by-product of image capture that obscures the desired information.
pixel
the individual units of intensity that make up an image.
raster graphics
images stored as a matrix of pixels.
RGB colour model
an additive colour model describing colour in a image with a combination of pixel intensities in three channels: red, green, and blue.
thresholding
the process of creating a binary version of a grayscale image, based on whether pixel values fall above or below a given limit or cut-off value.
TIFF (Tagged Image File Format)
a computer file format for storing raster graphics images; also abbreviated TIF
titration
a common laboratory method of quantitative chemical analysis to determine the concentration of an identified analyte (a substance to be analyzed)