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Flow Field Measurements by Particle Image Velocimetry (PIV) Techniques
Published in Je-Chin Han, Lesley M. Wright, Experimental Methods in Heat Transfer and Fluid Mechanics, 2020
For years, cameras with CCD sensors were the primary camera for researchers. Although the sensors were relatively expensive to manufacture, the noise level of the digital images was relatively low. As technology developed, especially for physically small cameras for security and phone applications, CMOS cameras rapidly developed. As with a CCD sensor, the CMOS sensor also captures light (photons) and converts the light to digital data. However, the CMOS camera requires significantly less power, and the digital conversion occurs much more quickly than with the CCD sensor. The low power consumption made this type of sensor very attractive for cell phone applications. The initial drawback of the CMOS sensor compared to the CCD sensor was the increased noise level in the digital images. Driven by multiple industries, the technology quickly matured, and the image quality has continuously improved. With the ability to convert and write digital data more quickly than with a CCD sensor, high-speed cameras with CMOS sensors became widely available.
Design and Fabrication of Optical and Fiber-Optic Humidity Sensors
Published in Ghenadii Korotcenkov, Handbook of Humidity Measurement, 2018
On account of the manufacturing distinctions, there have been some noticeable differences between CCD and CMOS sensors: CCD sensors create high-quality, low-noise images. CMOS sensors, traditionally, are more susceptible to noise.As each pixel on a CMOS sensor has several transistors located next to it, the light sensitivity of a CMOS chip tends to be lower. Many of the photons hitting the chip hit the transistors instead of the PD.CCDs use a process that consumes a lot of power. CCDs consume as much as 100 times more power than an equivalent CMOS sensor. This means that CMOS sensors should be considered as low-power devices, which have great battery life.CMOS chips can be fabricated on just about any standard silicon production line, so they tend to be extremely inexpensive compared to CCD sensors.CCD sensors have been mass produced for a longer period of time, so they are more mature. They tend to have higher quality and more pixels.
Color image processing for digital cameras
Published in Sharma Gaurav, Digital Color Imaging Handbook, 2017
In a typical CMOS sensor, each photosensitive cell contains a photodiode that converts light to electrons, a charge-to-voltage conversion section, a reset and select transistor, and an amplifier section. Overlaying the entire image-sensing array is a grid of metal interconnects to apply timing and readout signals, and output signal interconnects for each column. The column output signal is connected to a set of decode and readout electronics located outside of the light-sensitive array. This architecture allows the signals from the entire array, or from a subset of the array, to be read out by a simple addressing technique. This flexible readout, which allows a low-resolution image to be output quickly for camera exposure control and focusing, is not available with a CCD.
Production of orthophoto map using mobile photogrammetry and comparative assessment of cost and accuracy with satellite imagery for corridor mapping: a case study in Manesar, Haryana, India
Published in Annals of GIS, 2023
Manuj Dev, Shetru M Veerabhadrappa, Ashutosh Kainthola, Manas K Jha
The cameras used for our study are Canon electro optical system (EOS) 70D (Kissiyar et al., 2008) which is having 20.2 megapixels with advanced photosystem type-C (APS-C) CMOS-sensor and built in Wi-Fi and have digital imaging integrated circuit (DIGIC) 5+ image processor with ISO-range of 100–12800 (H: 25600) with electronic shutter. CMOS-sensor stands for complementary metal oxide semiconductor that converts the light into electrical signals. It allows shooting in a wide variety of lighting conditions. The touchscreen is 3-inches with 19-point cross type auto focus and 7.0 fps continuous burst shooting. Canon’s EOS 70D captures a massive 5472 × 3648-pixel resolution, which is good enough for even the largest enlargements and offers the best quality for significant cropping, while preserving the essence and detail of the scene. 14-bit signal processing ensures excellent tonal gradation and a wide (the International Organization for Standardization) range of 100–12800 (H: 25600) ensures excellent image capture even in dim lighting situations. Canon’s EOS 70D uses the DIGIC 5+ Image Processor to enhance the camera’s image sensor for faster data processing, improved noise reduction and even real-time compensation for chromatic aberration.