# US 2014/0152694 A1 · Merging Multiple Exposures to Generate a High Dynamic Range Image > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0152694 A1 - Document ID: US20140152694A1 - Status: Published application - Kind: A1 - Application number: 14/098,230 - Filed: 2013-12-05 - Published: 2014-06-05 - Earliest claimed: 2012-12-05 - Assignees: Texas Instruments Incorporated - Applicants: Texas Instruments Incorporated - Inventors: Rajesh Narasimha; Aziz Umit Batur - Web page: https://patentgrep.com/patent/US20140152694A1 ## CPC - G09G 5/377: for mixing or overlaying two or more graphic patterns (G09G5/02, G09G5/397 take precedence) - G06T 5/50: using two or more images, e.g. averaging or subtraction - G06T 5/92: based on global image properties - G06T 5/94: based on local image properties, e.g. for local contrast enhancement - G06V 10/60: relating to illumination properties, e.g. using a reflectance or lighting model - H04N 23/741: by increasing the dynamic range of the image compared to the dynamic range of the electronic image sensors - H04N 23/743: Bracketing, i.e. taking a series of images with varying exposure conditions - G06T 2207/10144: Varying exposure - G06T 2207/20012: Locally adaptive - G06T 2207/20021: Dividing image into blocks, subimages or windows - G06T 2207/20208: High dynamic range [HDR] image processing - H04N 25/589: with different integration times, e.g. short and long exposures - G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00) - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL - G06V: IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A method of generating a high dynamic range (HDR) image is provided that includes capturing a long exposure image and a short exposure image of a scene, computing a merging weight for each pixel location of the long exposure image based on a pixel value of the pixel location and a saturation threshold, and computing a pixel value for each pixel location of the HDR image as a weighted sum of corresponding pixel values in the long exposure image and the short exposure image, wherein a weight applied to a pixel value of the pixel location of the short exposure image and a weight applied to a pixel value of the pixel location in the pixel long exposure image are determined based on the merging weight computed for the pixel location and responsive to motion in a scene of the long exposure image and the short exposure image. ## Claims ### Claim 1 A method of generating a high dynamic range (HDR) image, the method comprising: capturing a long exposure image and a short exposure image of a scene; computing a merging weight for each pixel location of the long exposure image based on a pixel value of the pixel location and a saturation threshold; and computing a pixel value for each pixel location of the HDR image as a weighted sum of corresponding pixel values in the long exposure image and the short exposure image, wherein a weight applied to a pixel value of the pixel location of the short exposure image and a weight applied to a pixel value of the pixel location in the pixel long exposure image are determined based on the merging weight computed for the pixel location of the long exposure image and responsive to motion in a scene of the long exposure image and the short exposure image. ### Claim 2 (depends on 1) The method of claim 1, wherein computing a pixel value further comprises: computing a motion adaptation weight for each pixel location of the long exposure image; computing a weight for each pixel location of the long exposure image based on the merging weight computed for the pixel location of the long exposure image and the motion adaptation weight computed for each pixel location of the long exposure image; and computing a weight for each pixel location of the short exposure image by subtracting the weight computed for the pixel location in the long exposure image from one. ### Claim 3 (depends on 2) The method of claim 2, wherein computing a motion adaptation weight comprises: computing the motion adaptation weight for each 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. ### Claim 4 (depends on 2) The method of claim 2, wherein computing a motion adaptation weight comprises: computing the motion adaptation weight for each pixel location of the long exposure image based on deltas between pixel values of a block of pixel locations around the pixel location in the long exposure image and pixels values of a corresponding block of pixel locations around the pixel location in the short exposure image. ### Claim 5 (depends on 1) The method of claim 1, further comprising: adjusting gain difference between the long exposure image and the short exposure image. ### Claim 6 (depends on 1) The method of claim 1, further comprising: performing black level adjustment on the long exposure image and the short exposure image; and performing white balancing on the long exposure image and the short exposure image. ### Claim 7 An apparatus configured to generate a high dynamic range (HDR) image, the apparatus comprising: means for capturing a long exposure image and a short exposure image of a scene; means for computing a merging weight for each pixel location of the long exposure image based on a pixel value of the pixel location and a saturation threshold; and means for computing a pixel value for each pixel location of the HDR image as a weighted sum of corresponding pixel values in the long exposure image and the short exposure image, wherein a weight applied to a pixel value of the pixel location of the short exposure image and a weight applied to a pixel value of the pixel location in the pixel long exposure image are determined based on the merging weight computed for the pixel location of the long exposure image and responsive to motion in a scene of the long exposure image and the short exposure image. ### Claim 8 (depends on 7) The apparatus of claim 7, wherein the means for computing a pixel value further comprises: means for computing a motion adaptation weight for each pixel location of the long exposure image; means for computing a weight for each pixel location of the long exposure image based on the merging weight computed for the pixel location of the long exposure image and the motion adaptation weight computed for each pixel location of the long exposure image; and means for computing a weight for each pixel location of the short exposure image by subtracting the weight computed for the pixel location in the long exposure image from one. ### Claim 9 (depends on 8) The apparatus of claim 8, wherein the means for computing a motion adaptation weight computes the motion adaptation weight for each 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, ### Claim 10 (depends on 8) The apparatus of claim 8, wherein the means for computing a motion adaptation weight computes the motion adaptation weight for each pixel location of the long exposure image based on deltas between pixel values of a block of pixel locations around the pixel location in the long exposure image and pixels values of a corresponding block of pixel locations around the pixel location in the short exposure image. ### Claim 11 (depends on 7) The apparatus of claim 7, further comprising: means for adjusting gain difference between the long exposure image and the short exposure image. ### Claim 12 (depends on 7) The apparatus of claim 7, further comprising: means for performing black level adjustment on the long exposure image and the short exposure image; and means for performing white balancing on the long exposure image and the short exposure image.