# US 2010/0165178 A1 · Adjusting method of flash intensity > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2010/0165178 A1 - Document ID: US20100165178A1 - Status: Published application - Kind: A1 - Application number: 12/507,667 - Filed: 2009-07-22 - Published: 2010-07-01 - Earliest claimed: 2008-12-31 - Assignees: Altek Corporation - Inventors: Chan Min Chou; Chung Pin Lu - Web page: https://patentgrep.com/patent/US20100165178A1 ## CPC - G03B 13/32: Means for focusing - H04N 23/74: by influencing the scene brightness using illuminating means - G03B: APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR (optical parts of such apparatus G02B; photosensitive materials or processes for photographic purposes G03C; apparatus for processing exposed photographic materials G03D) - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract An adjusting method of flash intensity is applied in an image capture apparatus with a flash lamp, where two pre-flash images corresponding the object are retrieved under two different pre-flash lights, respectively, and then a flash intensity of main-flash light is calculated according to one of the retrieved pre-flash images, so as to retrieve a main-flash image corresponding the object under the main-flash light with the calculated main-flash light. ## Claims ### Claim 1 An adjusting method of flash intensity, applied in an image capture apparatus with a flash lamp, the adjusting method comprising: emitting a first pre-flash light by the flash lamp when the image capture apparatus photographs an object; retrieving a first pre-flash image corresponding the object under the first pre-flash light; emitting a second pre-flash light by the flash lamp when the image capture apparatus shoots the object, wherein flash intensity of the second pre-flash light is different from flash intensity of the first pre-flash light; retrieving a second pre-flash image corresponding the object under the second pre-flash light; selecting one of the first pre-flash image and the second pre-flash image to be a determined pre-flash image according to luminance of the first pre-flash image and luminance of the second pre-flash image; calculating flash intensity of a main-flash light by utilizing the determined pre-flash image; emitting the main-flash light with the calculated flash intensity by the flash lamp; retrieving a main-flash image corresponding the object under the main-flash light; and outputting the retrieved main-flash image. ### Claim 2 (depends on 1) The adjusting method of flash intensity according to claim 1, wherein the step of selecting one of the first pre-flash image and the second pre-flash image to be a determined pre-flash image comprises: obtaining a plurality of pixel values of the first pre-flash image; obtaining a plurality of pixel values of the second pre-flash image; comparing the plurality of pixel values of the first pre-flash image with a preset threshold value respectively, and accumulating a first number, wherein the first number is a number of pixel values that are greater than the preset threshold value among the plurality of pixel values of the first pre-flash image; comparing the plurality of pixel values of the second pre-flash image with the preset threshold value respectively, and accumulating a second number, wherein the second number is a number of pixel values that are greater than the preset threshold value among the plurality of pixel values of the second pre-flash image; comparing the first number with the second number to obtain a comparison result; and selecting one of the first pre-flash image and the second pre-flash image to be the determined pre-flash image according to the obtained comparison result. ### Claim 3 (depends on 2) The adjusting method of flash intensity according to claim 2, wherein the step of comparing the first number with the second number comprises: selecting the greater number from the first number and the second number, so as to take a pre-flash image corresponding to the greater number of the first pre-flash image and the second pre-flash image as the determined pre-flash image. ### Claim 4 (depends on 3) The adjusting method of flash intensity according to claim 3, wherein when the flash intensity of the first pre-flash light is greater than the flash intensity of the second pre-flash light and the first number is equal to the second number, the first pre-flash image is selected to be the determined pre-flash image. ### Claim 5 (depends on 1) The adjusting method of flash intensity according to claim 1, wherein when the flash intensity of the first pre-flash light is greater than the flash intensity of the second pre-flash light, the step of selecting one of the first pre-flash image and the second pre-flash image to be a determined pre-flash image comprises: averaging a plurality of luminance values of the first pre-flash image to get a first luminance value of the first pre-flash image; comparing the first luminance value with a luminance standard to get a comparison result; and selecting one of the first pre-flash image and the second pre-flash image as the determined pre-flash image according to the comparison result. ### Claim 6 (depends on 5) The adjusting method of flash intensity according to claim 5, wherein the luminance standard includes a luminance value of an overexposure image. ### Claim 7 (depends on 6) The adjusting method of flash intensity according to claim 6, wherein when the first luminance is greater than the luminance value of the overexposure image, the second pre-flash image is selected to be the determined pre-flash image. ### Claim 8 (depends on 6) The adjusting method of flash intensity according to claim 6, wherein when the first luminance is equal to or smaller than the luminance value of the overexposure image, the first pre-flash image is selected to be the determined pre-flash image. ### Claim 9 (depends on 5) The adjusting method of flash intensity according to claim 5, wherein the luminance standard includes a luminance value of an insufficient-exposure image. ### Claim 10 (depends on 5) The adjusting method of flash intensity according to claim 5, wherein the luminance standard is a luminance in a range of smaller than a luminance value of an overexposure image and greater than a luminance value of an insufficient-exposure image. ### Claim 11 (depends on 1) The adjusting method of flash intensity according to claim 1, wherein the step of outputting the retrieved main-flash image comprises: converting an image format of the retrieved main-flash image; and outputting the main-flash image with the converted image format. ### Claim 12 An adjusting method of flash intensity, applied in an image capture apparatus with a flash lamp, the adjusting method comprising: performing an automatic focusing before the image capture apparatus shoots an object; retrieving a focused image corresponding to the object after the automatic focusing is accomplished; emitting a first pre-flash light by the flash lamp; retrieving a first pre-flash image corresponding to the object under the first pre-flash light; emitting a second pre-flash light by the flash lamp, wherein a flash intensity of the second pre-flash light is different from a flash intensity of the first pre-flash light; retrieving a second pre-flash image corresponding to the object under the second pre-flash light; calculating a first luminance value of the first pre-flash image; calculating a second luminance value of the second pre-flash image; calculating a third luminance value of the focused image; comparing the first luminance value with the third luminance value to get a first difference value; comparing the second luminance value with the third luminance value to get a second difference value; comparing the first difference value with the second difference value to get a comparison result; selecting one of the first pre-flash image and the second pre-flash image to be a determined pre-flash image according to the comparison result; calculating a flash intensity by utilizing the determined pre-flash image; emitting a main-flash light with the calculated flash intensity by the flash lamp; retrieving a main-flash image corresponding to the object under the main-flash light; and outputting the retrieved main-flash image. ### Claim 13 (depends on 12) The adjusting method of flash intensity according to claim 12, wherein the step of calculating the first luminance value comprising: averaging a plurality of luminance values of the first pre-flash image to get the first luminance value. ### Claim 14 (depends on 12) The adjusting method of flash intensity according to claim 12, wherein the step of calculating the second luminance value comprising: averaging a plurality of luminance values of the second pre-flash image to get the second luminance value. ### Claim 15 (depends on 12) The adjusting method of flash intensity according to claim 12, wherein the step of calculating the third luminance value comprising: averaging a plurality of luminance values of the focused image to get the third luminance value. ### Claim 16 (depends on 12) The adjusting method of flash intensity according to claim 12, wherein when the first difference value is greater than the second difference value, the second pre-flash image is selected to be the determined pre-flash image; and wherein when the first difference value is equal to or smaller than the second difference value, the first pre-flash image is selected to be the determined pre-flash image. ### Claim 17 (depends on 12) The adjusting method of flash intensity according to claim 12, wherein the step of outputting the retrieved main-flash image comprises: converting an image format of the retrieved main-flash image; and outputting the main-flash image with the converted image format.