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What is Image Processing and Analysis?

Image processing is the manipulation of numeric data contained in a digital image for the purpose of improving or altering its visual appearance, either for aesthetic reasons or to make image features easier to see. This may be done by using image processing functions such as brightness and contrast enhancement or application of filters that reduce noise (irrelevant data) or sharpen edges. LUTs can be used to apply color to a grayscale image or to redefine the values of pixels in a color image so that certain types of image information become more obvious. For example, the pixels representing a particular type of ground cover or weather phenomenon shown in a satellite photo can be displayed as one bright color.

A major purpose of image processing is to alter the appearance of features in an image so that they may be better measured. Image analysis involves collecting data from digital images in the form of measurements (e.g., measuring the size of a tumor in an x-ray of a brain, or determining the amount of sulfur dioxide gas and ash in the plume of a volcano shown in a satellite photo). The accuracy and precision of measurements using digital image analysis is far greater than is possible with rulers and calipers.

Travel Within Data: The Power of Digital Images

Digital images are powerful because they are composed of thousands of pixels representing data that can be displayed in virtually any color or shade using computer software such as NASA Image2009. An image can be manipulated to bring out features not apparent at first glance, complex structures can be accurately selected and measured in many different ways, and time-lapse sequences can be animated.

Image processing and analysis allows learners to examine scientific information in ways that are not possible with textbooks, videos, interactive multimedia, and Internet Web pages. While other tools can show static images of structures, play animations, or display three-dimensional representations of objects, only image processing and analysis permits learners to travel within data and conduct scientific investigations on what they are visualizing.

Funded by the NIEHS


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is supported by Grant Number R44ES01255103 from the National Institutes of Environmental Health Sciences (NIEHS). The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIEHS or the National Institutes of Health.

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