An HDR imaging method with DTDI technology for push-broom cameras

Abstract

Abstract:Conventionally, high dynamic-range (HDR) imaging is based on taking two or more pictures of the same scene with different exposure. However, due to a high-speed relative motion between the camera and the scene, it is hard for this technique to be applied to push-broom remote sensing cameras. For the sake of HDR imaging in push-broom remote sensing applications, the present paper proposes an innovative method which can generate HDR images without redundant image sensors or optical components. Specifically, this paper adopts an area array CMOS (complementary metal oxide semiconductor) with the digital domain time-delay-integration (DTDI) technology for imaging, instead of adopting more than one row of image sensors, thereby taking more than one picture with different exposure. And then a new HDR image by fusing two original images with a simple algorithm can be achieved. By conducting the experiment, the dynamic range (DR) of the image increases by 26.02 dB. The proposed method is proved to be effective and has potential in other imaging applications where there is a relative motion between the cameras and scenes.

HDR Synthesis Technology for Spaceborne CMOS Cameras Based on Virtual Digital TDI

“…In recent years, in 2017, based on digital TDI technology, Taiji Lan et al [14]. proposed an adaptive histogram equalization algorithm with maximum entropy based on digital TDI technology to improve the ability of images to express dark or low-contrast target details, mainly focusing on the improvement of HDR synthesis technology; In 2018, Wu SUN [15] et al used digital TDI imaging technology for pushbroom cameras, simultaneously acquired images with different exposures in the same scene, and synthesized HDR images through image fusion method, mainly for HDR image synthesis with ideal conditions. However, the attitude stability of the spaceborne camera is not good enough.…”

Model for High Dynamic Range Imaging System Using Hybrid Feature Based Exposure Fusion

“…The basic method is to capture the image simultaneously with the different exposure and then irradiance spatial dimensions of the same scenario [7]. The captured images mapped to an HDR based efficient image reconstruction algorithm [8]. The exposure time of the camera depends on the lens aperture, shutter speed, and International Organization of Standardization (ISO) levels; the exposure time controls the intensity of the light incident on the image sensor [9].…”