Digitization of a video or electronic image captured through an optical microscope results in a dramatic increase in the ability to enhance features, extract information, or modify the image. When compared to the traditional mechanism of image capture, photomicrography on film, digital imaging and post-acquisition processing enables a reversible, essentially noise-free modification of the image as an ordered matrix of integers rather than a series of analog variations in color and intensity. This section addresses a variety of current topics in image acquisition and processing for optical microscopy.

Concepts in Digital Imaging Technology - Explore the basic concepts in digital imaging with our illustrated discussions and interactive Java tutorials. Topics covered include CCD operation, binning, blooming, image capture, dynamic range, electronic shutters, CCD clocking schemes, quantum efficiency, photodiodes, photomultipliers, digital manipulation of images and a wide spectrum of other issues in this emerging field.

Basic Properties of Digital Images - Continuous-tone images are produced by analog optical and electronic devices, which accurately record image data by several methods, such as a sequence of electrical signal fluctuations or changes in the chemical nature of a film emulsion that vary continuously over all dimensions of the image. In order for a continuous-tone or analog image to be processed or displayed by a computer, it must first be converted into a computer-readable form or digital format. This process applies to all images, regardless the origin and complexity, and whether they exist as black and white (grayscale) or full color. A digital image is composed of a rectangular (or square) pixel array representing a series of intensity values and ordered through an organized (x,y) coordinate system.

Electronic Imaging Detectors - The range of light detection methods and the wide variety of imaging devices currently available to the microscopist make the selection process difficult and often confusing. This discussion is intended to aid in understanding the basics of light detection and to provide a guide for selecting a suitable electronic detector (CCD or video camera system) for specific applications in optical microscopy.

Fundamentals of Video Imaging - Optical images produced in the microscope can be captured using either traditional film techniques, digitally with electronic detectors such as a charge-coupled device (CCD), or with a tube-type video camera. When a dynamic event must be recorded in real time, a video camera is often the most suitable resource for the task.

Introduction to CMOS Image Sensors - CMOS image sensors are designed with the ability to integrate a number of processing and control functions, which lie beyond the primary task of photon collection, directly onto the sensor integrated circuit. These features generally include timing logic, exposure control, analog-to-digital conversion, shuttering, white balance, gain adjustment, and initial image processing algorithms. Inexpensive CMOS image sensors are entering the field of optical microscopy in educational instruments that combine acceptable optical quality with user-friendly control and imaging software packages.

Basic Concepts in Digital Image Processing - Digital image processing enables the reversible, virtually noise-free modification of an image in the form of a matrix of integers instead of the classical darkroom manipulations or filtration of time-dependent voltages necessary for analog images and video signals. Even though many image processing algorithms are extremely powerful, the average user often applies operations to digital images without concern for the underlying principles behind these manipulations. The images that result from careless manipulation are often severely degraded or otherwise compromised with respect to those that could be produced if the power and versatility of the digital processing software were correctly utilized.

Recommended Strategy for Processing Digital Images - Depending upon the illumination conditions, specimen integrity, and preparation methods, digital images captured in the optical microscope may require a considerable amount of rehabilitation to achieve a balance between scientific accuracy, cosmetic equilibrium, and aesthetic composition. When first acquired by a charge-coupled device (CCD) or complementary metal oxide semiconductor (CMOS) image sensor, digital images from the microscope often suffer from poor signal-to-noise characteristics, uneven illumination, focused or defocused dirt and debris, glare, color shifts, and a host of other ailments that degrade overall image quality.

Deconvolution in Optical Microscopy - Deconvolution is a computationally intensive image processing technique that is being increasingly utilized for improving the contrast and resolution of digital images captured in the microscope. The foundations are based upon a suite of methods that are designed to remove or reverse the blurring present in microscope images induced by the limited aperture of the objective. Practically any image acquired on a digital fluorescence microscope can be deconvolved, and several new applications are being developed that apply deconvolution techniques to transmitted light images collected under a variety of contrast enhancing strategies. One of the most suitable subjects for improvement by deconvolution are three-dimensional montages constructed from a series of optical sections.

Digital Image Processing Interactive Java Tutorials - Explore the basic concepts of digital image processing applied to specimens captured in the microscope. Techniques reviewed include contrast, color balance, spatial resolution, image sampling frequency, geometric transformation, averaging, measurements, histogram manipulation, convolution kernels, filtering digital images, compression, noise reduction, and binary digital images.

Background Subtraction Toolkit - Because of the wide spectrum of illumination modes available with the optical microscope, images can suffer from brightness variations that are manifested by gradients appearing in the background. These fluctuations often lead to contrast and brightness deficiencies in the specimen region and can seriously affect the quality of an otherwise acceptable digital image. This section discusses important details concerning the Olympus Background Subtraction Toolkit, which is designed to assist image processing applications by providing uniform backgrounds for specimens captured digitally with an optical microscope.

Background Subtraction Toolkit Download - The Olympus digital microscope image Background Subtraction Toolkit is a stand-alone Java application program designed for the Windows operating system, which can be utilized to produce uniform backgrounds for digital images captured with this unique inverted optical microscope. Use this link to visit the download area for additional information and to download the software to client computers.

Olympus DP70 Digital Camera System - The latest generation of digital cameras designed for wide-ranging applications in optical microscopy combine excellent resolution, high sensitivity, and rapid data transfer to a host computer. The Olympus DP70 is a 12.5 million-pixel cooled digital color camera system that incorporates the latest innovations in imaging technology to enable the capture of superb images in the most demanding current microscopy applications, including differential interference contrast (DIC), darkfield, phase contrast, polarized light, and most widefield fluorescence techniques.

Olympus DP-10 Digital Camera - Olympus has designed a revolutionary new digital camera specifically designed for critical color photomicrography.