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Fundamentals of image acquisition and imaging protocol
Published in Michael O’Byrne, Bidisha Ghosh, Franck Schoefs, Vikram Pakrashi, Image-Based Damage Assessment for Underwater Inspections, 2019
Bidisha Ghosh, Michael O’Byrne, Franck Schoefs, Vikram Pakrashi
Cameras come in many different forms such as compact digital cameras, DSLRs (Digital Single-Lens Reflex), mirrorless cameras, action cameras, and smartphones. Compact digital cameras, also known as point-and-shoot cameras, are affordable, easy to use, lightweight, convenient, and they do not require additional lenses. However, some drawbacks are that they produce noisier images due to their smaller sensors, they have limited aperture and zoom range, and they often do not allow users to fully control settings such as the shutter speed and aperture.
Force-System Resultants and Equilibrium
Published in Richard C. Dorf, The Engineering Handbook, 2018
Digital cameras use a camera body and lens but record image data typically using an array of either CCD (charge-coupled device) or CMOS (complementary metal oxide semiconductor) detectors rather than film. In turn, the electrical signals generated by these detectors are stored digitally using various storage media. Although this process is not “photography” in the traditional sense (images are not recorded directly onto photographic film), it is often referred to as “digital photography” Of course, hardcopy photographs can also be converted into an array of digital picture elements (pixels) using some form of image scanner.
Digital Media
Published in Stephan S. Jones, Ronald J. Kovac, Frank M. Groom, Introduction to COMMUNICATIONS TECHNOLOGIES, 2015
Stephan S. Jones, Ronald J. Kovac, Frank M. Groom
Rather than using one-shot photographic film, a digital camera has a sensor to digitally record the image. The sensors (Exhibit 15.3) are typically complementary metal oxide semiconductor charged-coupled devices (CCDs), arranged with color filters (Exhibit 15.4). On the surface (the grid), each light sensor position is called a pixel (picture element). For a typical 35-mm film size, it takes 1.5 to 3 million pixels for comparable quality. Each pixel sees the light hitting it and reads it in a digitized bit form of 8, 10, or 12 bits (bit resolution). Color filters are used to capture the different sensitivities of either the additive or subtractive primary colors. If the camera is additive, the additive primary filters red, green, and blue are used. RGB added together makes white light. For the subtractive concept, it is cyan, magenta, and yellow filters that are used. Cyan, magenta, and yellow together make black.
Identification of defective weld and quality monitoring in manual metal arc welding process using surface level image features
Published in Welding International, 2022
Bipul Das, Aman Dwivedi, Mehdi Mehtab Mirad
A machine vision system cannot function without a clear image, so it is very important to guarantee a steady environment for the camera to capture the images. Digital cameras have an image sensor that is responsible for capturing the image, equivalent to a film on a traditional camera. The most used image sensor type in digital cameras is CMOS (complementary metal-oxide-semiconductor). The captured images are very similar to a picture of the scene as seen by a human eye. The CMOS camera should have the following specifications, such as high resolution, low power consumption, improved colour concept, and low light sensor.