Merging multiple exposures to generate a high dynamic range image

An apparatus configured to generate a high dynamic range (HDR) image, the apparatus comprising:

• one or more processors;
• and
• a non-transitory computer readable storage medium storing a program for execution by the one or more processors, the program including instructions to:
• receive, from an HDR sensor module, a long exposure image of a scene;
• receive, from the HDR sensor module, a short exposure image of the scene;
• perform black level adjustment on the long exposure image and the short exposure image;
• perform white balancing on the long exposure image and the short exposure image;
• compute a merging weight for a pixel location of the long exposure image by comparing a pixel value at the pixel location of the long exposure image to a saturation threshold;
• compute a motion adaptation weight for the pixel location of the long exposure image, based on a delta between a pixel value of the pixel location in the long exposure image and a pixel value of the pixel location in the short exposure image;
• compute a long exposure weight based on the motion adaptation weight and the merging weight for the pixel location of the long exposure image;
• compute a short exposure weight based on the long exposure weight;
• compute a pixel value for the pixel location of the HDR image to be a sum of the pixel value of the long exposure image weighted by the long exposure weight and the pixel value of the short exposure image weighed by the short exposure weight, to generate a merged HDR image comprising N bit data;
• adaptively map the HDR image to generate an output HDR image having M bit data, wherein M is less than N;
• and
• output, to a display device, the output HDR image.

A non-transitory computer-readable storage medium storing a program for execution by one or more processors, for generating a high dynamic range (HDR) image, the program including instructions to:

• receive, from an HDR sensor module, a long exposure image of a scene;
• receive, from the HDR sensor module, a short exposure image of the scene;
• compute a merging weight for each pixel location of the long exposure image by comparing a pixel value at the pixel location of the long exposure image to a saturation threshold;
• compute a motion adaptation weight for the pixel location of the long exposure image based on a delta between a pixel value of the pixel location in the long exposure image and a pixel value of the pixel location in the short exposure image;
• compute a long exposure weight based on the motion adaptation weight and the merging weight for the pixel location of the long exposure image;
• compute a short exposure weight based on the long exposure weight bar subtracting the long exposure weight for the pixel location in the long exposure image from one;
• compute a pixel value for the pixel location of the HDR image to be a sum of the pixel value of the long exposure image weighted by the long exposure weight and the pixel value of the short exposure image weighted by the short exposure weight, to generate a merged HDR image comprising N bit data;
• adaptively map the HDR image to generate an output HDR image having M bit data, wherein M is less than N;
• and
• output, to a display device, the output HDR image.