# US 7,609,857 B2 · Method and device for recognizing obstruction of view in image sensor systems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,609,857 B2 - Document ID: US7609857B2 - Status: Granted - Kind: B2 - Application number: 10/501,253 - Filed: 2002-11-22 - Published: 2005-11-17 - Granted: 2009-10-27 - Earliest claimed: 2002-01-17 - Assignees: Robert Bosch GmbH - Inventors: Matthias Franz - Web page: https://patentgrep.com/patent/US7609857B2 ## CPC - B60S 1/0822: {characterized by the arrangement or type of detection means} - B60S 1/0844: {including a camera} - G06T 7/0002: {Inspection of images, e.g. flaw detection} - G06T 7/0004: {Industrial image inspection} - G06V 20/56: exterior to a vehicle by using sensors mounted on the vehicle - G06T 2207/30168: Image quality inspection - G06T 2207/30252: Vehicle exterior; Vicinity of vehicle - H04N 17/002: {for television cameras} - B60S: SERVICING, CLEANING, REPAIRING, SUPPORTING, LIFTING, OR MANOEUVRING OF VEHICLES, NOT OTHERWISE PROVIDED FOR - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL - G06V: IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A method and a device for recognizing visual obstructions in image sensor systems are provided. A signal is produced, based on the analysis of the recorded image from the image sensor, which indicates the presence and, optionally, the type, of the visual obstruction on a windshield, for example. ## Claims ### Claim 1 A method for recognizing a visual obstruction using an image sensor associated with a vehicle, comprising: recording an image by the image sensor, wherein the image sensor is focused on an external region beyond the vehicle such that a visual obstruction on the vehicle is imaged; analyzing the image recorded by the image sensor, wherein at least one of a presence and a type of a visual obstruction is determined by the analysis of the image, wherein the analysis includes measuring a blurriness of at least a portion of the image; producing a signal which indicates one of the presence and the type of the visual obstruction; and controlling downstream systems based on the signal; wherein an analysis of at least one image recorded after an initial wiping operation on a windshield of a motor vehicle is used to determine whether to initiate a next wiping operation, and wherein the determination regarding the next wiping operation is based on blurriness of a first image that was recorded immediately after the initial wiping operation in comparison to blurriness of an image recorded subsequent to the first image. ### Claim 2 (depends on 1) The method of claim 1, wherein the at least one of the presence and the type of the visual obstruction is determined by measuring a relative blurriness of different parts of the image. ### Claim 3 (depends on 1) The method of claim 1, wherein the blurriness is measured based on one of a contrast spectrum of the image, a Fourier spectrum, and a autocorrelation function of the image. ### Claim 4 (depends on 1) The method of claim 1, wherein the at least one of the presence and the type of visual obstruction is determined based on a measured distribution of the blurriness by comparison with reference distributions. ### Claim 5 (depends on 1) The method of claim 1, further comprising: turning on a windshield light if a scene has a contrast below a predetermined threshold. ### Claim 6 A device for identifying a visual obstruction, comprising: an image sensor for recording an image, wherein the image sensor is focused on an external region beyond the vehicle such that a visual obstruction on the vehicle is imaged; and an evaluation unit for analyzing the image recorded by the image sensor; wherein the evaluation unit outputs a signal that indicates at least one of a presence and a type of the visual obstruction based on the analysis of the image, wherein the analysis includes measuring a blurriness of at least a portion of the image; and wherein the signal is used to control downstream systems, and wherein the determination regarding the next wiping operation is based on blurriness of a first image that was recorded immediately after the initial wiping operation in comparison to blurriness of an image recorded subsequent to the first image. ### Claim 7 (depends on 6) The device of claim 6, wherein the downstream systems include at least one of windshield wipers, windshield heating systems, and windshield washer systems. ### Claim 8 (depends on 6) The device of claim 6, wherein the at least one of the presence and the type of the visual obstruction is determined by measuring a relative blurriness of different parts of the image. ### Claim 9 (depends on 6) The device of claim 6, wherein the blurriness is measured based on one of a contrast spectrum of the image, a Fourier spectrum, and a autocorrelation function of the image. ### Claim 10 (depends on 6) The device of claim 6, wherein the at least one of the presence and the type of visual obstruction is determined based on a measured distribution of the blurriness by comparison with reference distributions. ### Claim 11 (depends on 6) The device of claim 6, wherein an analysis of at least one image recorded after an initial wiping operation on a windshield of a motor vehicle is used to determine whether to initiate a next wiping operation. ### Claim 12 (depends on 6) The device of claim 6, further comprising: an arrangement to turn on a windshield light if a scene has a contrast below a predetermined threshold. ### Claim 13 A device for identifying a visual obstruction, comprising: an image sensor for recording an image, wherein the image sensor is focused on an external region beyond the vehicle such that a visual obstruction on the vehicle is imaged; and an evaluation unit for analyzing the image recorded by the image sensor; wherein: the evaluation unit outputs a signal that indicates at least one of a presence and a type of the visual obstruction based on the analysis of the image, wherein the analysis includes measuring a blurriness of at least a portion of the image, the signal is used to control downstream systems, the downstream systems include at least one of windshield wipers, windshield heating systems, and windshield washer systems, the blurriness is measured based on one of a contrast spectrum of the image, a Fourier spectrum, and a autocorrelation function of the image, and an analysis of at least one image recorded after an initial wiping operation on a windshield of a motor vehicle is used to determine whether to initiate a next wiping operation, and wherein the determination regarding the next wiping operation is based on blurriness of a first image that was recorded immediately after the initial wiping operation in comparison to blurriness of an image recorded subsequent to the first image. ### Claim 14 (depends on 13) The device of claim 13, wherein the at least one of the presence and the type of the visual obstruction is determined by measuring a relative blurriness of different parts of the image. ### Claim 15 (depends on 13) The device of claim 13, wherein the at least one of the presence and the type of visual obstruction is determined based on a measured distribution of the blurriness by comparison with reference distributions. ### Claim 16 (depends on 13) The device of claim 13, further comprising: an arrangement to turn on a windshield light if a scene has a contrast below a predetermined threshold. ### Claim 17 A method for recognizing a visual obstruction using an image sensor associated with a vehicle, comprising: recording an image by the image sensor, wherein the image sensor is focused on an external region beyond the vehicle such that a visual obstruction on the vehicle is imaged; analyzing the image recorded by the image sensor, wherein at least one of a presence and a type of a visual obstruction is determined by the analysis of the image, wherein the analysis includes measuring a blurriness of at least a portion of the image; producing a signal which indicates one of the presence and the type of the visual obstruction; and controlling downstream systems based on the signal; wherein: the downstream systems include at least one of windshield wipers, windshield heating systems, and windshield washer systems, the blurriness is measured based on one of a contrast spectrum of the image, a Fourier spectrum, and a autocorrelation function of the image, and wherein an analysis of at least one image recorded after an initial wiping operation on a windshield of a motor vehicle is used to determine whether to initiate a next wiping operation, and wherein the determination regarding the next wiping operation is based on blurriness of a first image that was recorded immediately after the initial wiping operation in comparison to blurriness of an image recorded subsequent to the first image. ### Claim 18 (depends on 17) The method of claim 17, wherein the at least one of the presence and the type of the visual obstruction is determined by measuring a relative blurriness of different parts of the image. ### Claim 19 (depends on 17) The method of claim 17, wherein the at least one of the presence and the type of visual obstruction is determined based on a measured distribution of the blurriness by comparison with reference distributions. ### Claim 20 (depends on 17) The method of claim 17, further comprising: turning on a windshield light if a scene has a contrast below a predetermined threshold.