HDR reconstruction for alternating gain (ISO) sensor readout

Eurographics 2014
S. Hajisharif, J. Unger, J. Kronander
C-Research, Media and Information Technology, Linköping University


Figure: In this paper, we present a method for extending the dynamic range of images by capturing two ISO-settings within the same image. We use Canon 5D DSLR cameras as out experimental platform.


Modern image sensors are becoming more and more flexible in the way an image is captured. In this paper, we focus on sensors that allow the per pixel gain to be varied over the sensor and develop a new technique for efficient and accurate reconstruction of high dynamic range (HDR) images based on such input data. Our method estimates the radiant power at each output pixel using a sampling operation which performs color interpolation, re-sampling, noise reduction and HDR-reconstruction in a single step. The reconstruction filter uses a sensor noise model to weight the input pixel samples according to their variances. Our algorithm works in only a small spatial neighbourhood around each pixel and lends itself to efficient implementation in hardware. To demonstrate the utility of our approach we show example HDR-images reconstructed from raw sensor data captured using off-the shelf consumer hardware which allows for two different gain settings for different rows in the same image. To analyse the accuracy of the algorithm, we also use synthetic images from a camera simulation software.

Paper: Paper preprint (.pdf) (34.5MB)
author = {Saghi Hajisharif and Jonas Unger and Joel Kronander},
title = {{HDR} reconstruction for alternating gain {(ISO)} sensor readout},
booktitle = {Proceedings of Eurographics Short Papers},
location = {Strasbourg, France},
month = {May},
year = {2014},


Jonas Unger 2019