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Plant Disease Detection Using Imaging Sensors, Deep Learning and Machine Learning for Smart Farming
Published in Punit Gupta, Dinesh Kumar Saini, Rohit Verma, Healthcare Solutions Using Machine Learning and Informatics, 2023
Chanchal Upadhyay, Hemant K Upadhyay, Sapna Juneja, Abhinav Juneja
Image sensors are used to create an image of an object that detects relevant information and converts the variable attenuation of light waves into signals, which transmit information by short bursts of current (Mishra et al., 2020, Zhang et al., 2019). Image sensors are used in both analog and digital imaging devices such as camera phone, optical mouse, digital camera, medical imaging modules, radar and sonar. The first digital cameras used charge-coupled devices, which facilitated the movement of electric charge through the device so that it could be modified and used in the same way as above. Image sensors work in a similar way, converting input photons into a signal that can be read and interpreted.
Volunteered remote sensing data generation with air passengers as sensors
Published in International Journal of Digital Earth, 2021
Chisheng Wang, Yongquan Wang, Leyang Wang, Zhongwen Hu, Shaobiao Zhang, Shuanglong Wang, Wenqun Xiu, Hongxing Cui, Dan Wang, Qingquan Li
Generally, high-accuracy data will be achieved with more expensive cameras, which include lenses with high optical quality. Larger sensor sizes and fields of view are preferred for generating high-quality remote sensing products. Many types of portable customer-level camera devices can be used, including digital single-lens reflex (DSLR), point-and-shoot, bridge cameras, and camera phones. A DSLR is a camera with the reflex design scheme that can present a direct optical view through the lens and capture very high-quality photos. Point-and-shoot cameras are compact and were designed to be affordable, convenient, and easy to use. Bridge cameras are cameras that fill the gap between point-and-shoot cameras and DSLRs. Camera phones are mobile phones which is able to capture photographs, mostly referring to smartphones. Theare is no doubt that DSLR perform the best in key camera characteristics involved in remote sensing and photogrammetry, including focal length, imaging size, sampling, principal point, and lens distortion. However, according to DxOMark's summary of the current state of the camera industry, the performance gap between smartphones and DSLRs is narrowing (DXOMARK 2020a). Smartphone is now widely applied for photogrammetry (Dabove, Grasso, and Piras 2019). A study using Iphone 5 and Canon G9 shows that no significant differences were found between the models in a comparative analysis (Wróżyński et al. 2017). The volumes of the models differed from the actual volume just by 0.7 and 2 h. According to Statista (2020), there is 3.2 billion smartphone users in the world today (Figure 3a). This data means that 40 percentage of the world's 7.6 billion inhabitants now have a smartphone today.