US 12,482,079 B2
System and method for removing haziness in digital images
Mahendra Kumar Angamuthu Ganesan, Chennai (IN); Prabu Palaniappan, Namakkal (IN); Arun Anandan, Chennai (IN); Swaran Thekkevavanoor, Chennai (IN); and Abdul A. Mahaboob Basha, Chennai (IN)
Assigned to Caterpillar Inc., Peoria, IL (US)
Appl. No. 17/917,303
Filed by Caterpillar Inc., Peoria, IL (US)
PCT Filed Mar. 31, 2021, PCT No. PCT/US2021/025091
§ 371(c)(1), (2) Date Oct. 6, 2022,
PCT Pub. No. WO2021/211297, PCT Pub. Date Oct. 21, 2021.
Claims priority of application No. 202011016605 (IN), filed on Apr. 17, 2020.
Prior Publication US 2023/0107829 A1, Apr. 6, 2023
Int. Cl. G06T 5/80 (2024.01); G06T 3/40 (2024.01); G06T 5/20 (2006.01); G06V 10/60 (2022.01); G06V 10/75 (2022.01)
CPC G06T 5/80 (2024.01) [G06T 3/40 (2013.01); G06T 5/20 (2013.01); G06V 10/60 (2022.01); G06V 10/751 (2022.01); G06T 2207/20028 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method for removing haziness in a digital image, the method comprising:
receiving, by a processing unit, an input digital image from an image capturing device, the input digital image depicting at least some haze content;
downscaling, by the processing unit, the input digital image to obtain a low-resolution image, wherein the low-resolution image comprises pixels having intensity values associated with multiple color channels;
determining, by the processing unit, a dark channel image corresponding to the low-resolution image by:
identifying minimum intensity dark channels associated with respective local patches of the pixels of the low-resolution image, wherein:
a minimum intensity dark channel associated with a particular local patch is identified as one color channel of the multiple color channels that is associated with lowest intensity values within the particular local patch; and
generating the dark channel image using the minimum intensity dark channels associated with the respective local patches;
determining, by the processing unit, an atmospheric light value associated with the low-resolution image;
determining, by the processing unit, a transmission map of the low-resolution image by computing a transmission ratio for each of the respective local patches, based on:
the minimum intensity dark channels associated with the respective local patches in the dark channel image, and
the atmospheric light value;
scaling, by the processing unit, the transmission map to a corresponding magnitude of the input digital image to generate a scaled transmission map;
generating, by the processing unit, a de-hazed output image by applying the scaled transmission map and the atmospheric light value to the input digital image; and
displaying, by the processing unit, the de-hazed output image on a display unit.