# US 8,570,396 B2 · Multiple exposure high dynamic range image capture > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,570,396 B2 - Document ID: US8570396B2 - Status: Granted - Kind: B2 - Application number: 13/091,068 - Filed: 2011-04-20 - Published: 2011-09-01 - Granted: 2013-10-29 - Earliest claimed: 2009-04-23 - Assignees: CSR Technology Inc. - Applicants: Guy Rapaport - Inventors: Guy Rapaport - Web page: https://patentgrep.com/patent/US8570396B2 ## CPC - G06F 3/1454: {involving copying of the display data of a local workstation or window to a remote workstation or window so that an actual copy of the data is displayed simultaneously on two or more displays, e.g. teledisplay} - G09G 5/06: using colour palettes, e.g. look-up tables - G09G 5/14: Display of multiple viewports - H04N 23/60: Control of cameras or camera modules - H04N 23/68: for stable pick-up of the scene, e.g. compensating for camera body vibrations - H04N 23/741: by increasing the dynamic range of the image compared to the dynamic range of the electronic image sensors - G09G 2320/02: Improving the quality of display appearance - G09G 2320/0285: using tables for spatial correction of display data - G09G 2340/0414: Vertical resolution change - G09G 2340/0421: Horizontal resolution change - G09G 2340/06: Colour space transformation - G09G 2340/10: Mixing of images, i.e. displayed pixel being the result of an operation, e.g. adding, on the corresponding input pixels - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - 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) - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract Techniques for creating a High Dynamic Range (HDR) image within a consumer grade digital camera from a series of images of a scene captured at different exposure levels, and displaying the HDR image on the camera's built-in display are provided. The approach employs mixing images of the series to incorporate both scene shadow and highlight details, and the removing of “ghost” image artifacts appearing in the mixed HDR image resulting from movement in the scene over the time the series images are captured. The low computational resource utilization of the image mixing and ghost removal processing operations, along with the ability to commence image mixing and ghost removal prior to the acquisition of all series images, can significantly reduce the time required to generate and display a tone mapped HDR image. ## Claims ### Claim 1 A method for detecting local motion between a reference image and a plurality of comparison images, comprising: defining a number of luma thresholds that determine a group of reference image luma value ranges in which a particular comparison image is selected, the number corresponding to the number of comparison images; defining a difference threshold function that sets threshold values according to luma values of the reference image; for each particular comparison image, producing an intermediate detection map denoting local motion between the reference image and the particular comparison image by applying the threshold values on a difference image formed by comparing the reference image and the particular comparison image, wherein the intermediate detection map is based on pixels within a reference image luma value range that corresponds to the particular comparison image; and outputting a final detection map that is a union of the intermediate detection maps. ### Claim 2 (depends on 1) The method of claim 1 wherein a relatively lower luma comparison image is selected in relatively higher reference image luma value ranges, and vice-versa. ### Claim 3 (depends on 1) The method of claim 1 wherein the luma threshold value set varies with difference image luma values. ### Claim 4 (depends on 1) The method of claim 1 wherein the intermediate detection map is produced by: considering pixels with luma values in the range corresponding to the particular comparison image; calculating a standard deviation and a mean of the considered pixels; normalizing the considered pixels to have a same standard deviation and a same mean for the reference image and the particular comparison image; creating an absolute difference map of the considered pixels; and using the difference threshold function on the difference map to identify local motion detections. ### Claim 5 A system for detecting local motion between a reference image and a plurality of comparison images, comprising: a processor that: defines a number of luma thresholds that determine a group of reference image luma value ranges in which a particular comparison image is selected, the number corresponding to the number of comparison images; defines a difference threshold function that sets threshold values according to luma values of the reference image; for each particular comparison image, produces an intermediate detection map denoting local motion between the reference image and the particular comparison image by applying the threshold values on a difference image formed by comparing the reference image and the particular comparison image, wherein the intermediate detection map is based on pixels within a reference image luma value range that corresponds to the particular comparison image; and outputs a final detection map that is a union of the intermediate detection maps. ### Claim 6 (depends on 5) The system of claim 5 wherein a relatively lower luma comparison image is selected in relatively higher reference image luma value ranges, and vice-versa. ### Claim 7 (depends on 5) The system of claim 5 wherein the luma threshold value set varies with difference image luma values. ### Claim 8 (depends on 5) The system of claim 5 wherein the intermediate detection map is produced by: considering pixels with luma values in the range corresponding to the particular comparison image; calculating a standard deviation and a mean of the considered pixels; normalizing the considered pixels to have a same standard deviation and a same mean for the reference image and the particular comparison image; creating an absolute difference map of the considered pixels; and using the difference threshold function on the difference map to identify local motion detections.