Reference

Last updated on 2023-04-26 | 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)