Experimenting with custom-programming of cameras can be difficult. Most consumer cameras are protected to prevent users from reprogramming them. Industrial cameras can be flexibly controlled by an external computer, but are generally not standalone programmable devices. However, various inexpensive camera modules, designed largely to be used for building IoT (Internet of Things) devices, combine extensive programmability with a camera in a compact, low-power, module. One of the smallest and least expensive, the ESP32-CAM module, combines a 2MP Omnivision OV2640 camera with a dual-core 32-bit processor, 802.11 WiFi and BlueTooth as well as wired I/O interfaces, a mi-croSD slot, low power modes, etc., all supported by the Arduino programming environment and a rich collection of open source libraries. Why not use it for programmable camera research?This paper describes how the ESP32-CAM had to be adapted to enable use in a variety of experimental cameras. For example, some of these cameras do not use the lens screwed and glued onto the OV2640, and replacing this lens revealed a number of issues ranging from spectral response to adjustment of lens corrections. There are numerous strange interactions between different functions that end-up sharing the same I/O pins, so work-arounds were needed. It also was necessary to devise ways to handle various higher-level issues such as implementation of a live view and synchronization across cameras. However, the key problems have been resolved with open source software and hardware designs described here.
A composite image is an image created by combining portions of multiple separately-captured images. Stitching of captures of tiled portions of a larger scene can be used to produce a single composite image (a panorama) with a wider view angle and higher total resolution. Image stacking is a different type of compositing, in which the scene is not changing significantly across captures, but camera parameters might be systematically varied. Focus stacking can extend the depth of field, aperture stacking can implement apodization shaping the out-of-focus point spread function, and noise and motion reduction can be accomplished even using the same camera parameters for each capture to be stacked. These and other compositing methods are well known and commonly used, but the same fixed pattern is commonly used for ordering of captures and choice of capture parameters. This paper examines the problem of static, pseudo-static, or dynamic determination of the optimal capture parameters and ordering.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.