Utilizing three overlapping images for exposure correction during panoramic image stitching

摘要

A method for panorama exposure correction can begin with the receiving of a hemispherical-coverage panoramic digital image set by a panoramic image stitching system. The hemispherical-coverage panoramic digital image set can be comprised of a ceiling image and at least three side images that are all captured simultaneously. The images of the image set can be aligned to create a panoramic image. Based on the alignment, overlapping regions between two adjacent side images and the ceiling image can be identified, the placement of blending seams can be determined, and the region of each image affected by a exposure correction can be determined. The exposure correction for each identified overlapping region can be determined. The exposure of the affected region of each image can then be adjusted in accordance with the determined exposure correction. A gradient blending can be performed for a predefined area across the blending seams.

主权项

1. A method for panorama exposure correction comprising:
receiving of a hemispherical-coverage panoramic digital image set by a panoramic image stitching system, wherein the hemispherical-coverage panoramic digital image set is captured by a hemispherical-coverage panoramic digital image capture device that utilizes a hemispherical panoramic camera module comprising at least three side digital cameras in fixed positions circumferentially-parallel with a base of the hemispherical panoramic camera module and one ceiling digital camera in a fixed upwards position perpendicular to the at least three circumferentially-parallel digital cameras, wherein a field of view of each side digital camera overlaps with the field of view of its neighboring side digital cameras and the field of view of the ceiling digital camera, wherein said hemispherical-coverage panoramic digital image set is then comprised of a ceiling image and at least three side images that are all captured simultaneously; aligning images of the hemispherical-coverage panoramic digital image set to create a panoramic image; based on said alignment, identifying overlapping regions between two adjacent side images and the ceiling image; based on said alignment and identified overlapping regions, determining a placement of blending seams, wherein a blending seam is an artificial vertical line that acts as a boundary between exposure corrections performed for two overlapping regions, wherein the blending seam is placed at a halfway point between the two overlapping regions in a non-terminal side image, wherein the blending seams are extended onto the ceiling image; based on said alignment and identified overlapping regions, determining a region of each image to be affected by a exposure correction of the overlapping region, wherein an affected region of a terminal side image is an entirety of the terminal side image, wherein the affected region of the non-terminal side image is horizontally bounded by an edge contained in the overlapping region and the blending seam of the non-terminal side image, wherein the affected region of the ceiling image is horizontally bounded by one of a terminating edge and the blending seam and two blending seams; determining the exposure correction for each identified overlapping region, wherein the exposure correction normalizes exposure between the two adjacent side images and ceiling image; adjusting a exposure of the affected region of each image contributing to the overlapping region in accordance with the determined exposure correction; and performing a gradient blending for a predefined area across the blending seams.