Apparatus and method for detecting flicker noise and computer readable medium stored thereon computer executable instructions for performing the method
An apparatus for detecting flicker noise disclosed in the present invention comprises an output unit for outputting a standard data for flicker noise judgment using a statistical calculation value for each calculated line based on brightness information of pixels for each line of an object image for flicker noise detection; a flicker line detection unit for detecting flicker lines, namely, lines corresponding to the standard data where the distance between the lines are within a predetermined allowance of a regular interval; and a judgment unit for comparing the number of the detected flicker lines with a standard number for flicker noise judgment to judge if the object image is a flicker noise image. The present invention can realize a method for detecting flicker noise, in which an image obtained with the reduced calculation time and use of a minimum memory has a robust in characteristics of a subject.
1. An apparatus for detecting flicker noise, comprising:
an output unit for outputting a standard data for flicker noise judgment using a statistical calculation value for each line where the statistical calculation values are calculated based on brightness information of pixels for each line of an object image, and which include a first output unit for outputting a first data for each line of the object image, where the first data is a statistical calculation value of brightness information of pixels corresponding to one line in the object image, and a filtering unit for low-pass filtering the first data for each line;
a flicker line detection unit for detecting flicker lines by identifying lines corresponding to the standard data where the distance between the lines are within a predetermined allowance of a regular interval; and
a judgment unit for comparing the number of the detected flicker lines with a standard number for flicker noise judgment to judge if the object image is a flicker noise image,
wherein the filtering unit performs a low-pass filtering only for each of the first data corresponding to lines of a predetermined number from among lines forming the object image,
wherein the standard number corresponds to 60% or more of a value obtained by dividing a height of the object image by a size of an interval between flicker lines.
2. The apparatus for detecting flicker noise according to claim 1 ,
wherein the output unit includes:
a standard data output unit for outputting a standard data, where the standard data is a first data greater than a first data of a previous line and greater than a first data of a next line among the first data.
3. The apparatus for detecting flicker noise according to claim 2 ,
wherein the standard data output unit outputs a standard data, namely, a second data greater than a second data of a previous line and greater than a second data of a next line where a second data is the low-pass filtered first data.
4. The apparatus for detecting flicker noise according to claim 3 , wherein the filtering unit performs a low-pass filtering for each of the first data corresponding to at least six to eight lines among lines forming the object image.
5. The apparatus for detecting flicker noise according to claim 2 ,
wherein the first output unit outputs the first data using brightness information of all pixels corresponding to one line.
6. The apparatus for detecting flicker noise according to claim 1 ,
wherein the statistical calculation value is a value obtained by dividing the sum of brightness information of pixels corresponding to one line in the object image by a number that is selected from numbers ranging from ‘1’ to the number of pixels corresponding to one line.
7. The apparatus for detecting flicker noise according to claim 1 ,
wherein, in the case that the intervals between the flicker lines are not equal to each other, the size of the interval between flicker lines is an average value of sizes of intervals between flicker lines having non-equal intervals.
8. The apparatus for detecting flicker noise according to claim 1 ,
wherein, in the case that the intervals between flicker lines are not equal to each other, the size of the interval between flicker lines is the size of the most frequent interval.
9. The apparatus for detecting flicker noise according to claim 1 ,
wherein, in the case that the intervals between flicker lines are not equal to each other, the number of flicker lines compared with the standard number is the sum of the number of flicker lines having nonequal intervals.
10. The apparatus for detecting flicker noise according to claim 1 ,
wherein, in the case that the intervals between flicker lines are not equal to each other, the number of flicker lines compared with the standard number is the number of the flicker lines having most frequent interval.
11. A method for detecting flicker noise, comprising:
an output step for outputting a standard data for flicker noise judgment using a statistical calculation value for each line where the statistical calculation values are calculated based on brightness information of pixels for each line of an object image;
a flicker line detection step for detecting flicker lines by identifying lines corresponding to the standard data where the distance between the lines are within a predetermined allowance of a regular interval; and
a judgment step for comparing the number of the detected flicker lines with a standard number for flicker noise judgment to judge if the object image is a flicker noise image
wherein the output step include a first output step for outputting a first data for each line of the object image, where the first data is a statistical calculation value of brightness information of pixels corresponding to one line in the object image, and a filtering step for low-pass filtering the first data for each line,
wherein, in the filtering step, a low-pass filtering is performed only for each of the first data corresponding to lines of a predetermined number from among lines forming the object image,
wherein the standard number corresponds to 60% or more of a value obtained by dividing a height of the object image by a size of an interval between flicker lines.
12. The method for detecting flicker noise according to claim 11 ,
wherein the output step includes:
a standard data output step for outputting a standard data, where the standard data is a first data greater than a first data of a previous line and greater than a first data of a next line among the first data.
13. The method for detecting flicker noise according to claim 12 ,
wherein, in the standard data output step, a standard data, namely, a second data greater than a second data of a previous line and greater than a second data of a next line is outputted where a second data is the low-pass filtered first data.
14. The method for detecting flicker noise according to claim 13 , wherein, in the filtering step, a low-pass filtering is performed for each of the first data corresponding to at least six to eight lines among lines forming the object image.
15. The method for detecting flicker noise according to claim 12 ,
wherein, in the first output step, the first data, namely, the statistical calculation value is outputted using brightness information of all pixels corresponding to one line.
16. The method for detecting flicker noise according to claim 11 ,
wherein the statistical calculation value is a value obtained by dividing the sum of brightness information of pixels corresponding to one line in the object image by a number that is selected from numbers ranging from “1” to the number of pixels corresponding to one line.
17. The method for detecting flicker noise according to claim 11 ,
wherein, in the case that the intervals between flicker lines are not equal to each other, the size of an interval between the flicker lines is an average value of sizes of intervals between flicker lines having nonequal intervals.
18. The method for detecting flicker noise according to claim 11 ,
wherein, in the case that the intervals between flicker lines are not equal to each other, the size of an interval between the flicker lines is the size of the most frequent interval.
19. The method for detecting flicker noise according to claim 11 ,
wherein, in the case that the intervals between flicker lines are not equal to each other, the number of flicker lines compared with the standard number is the sum of the numbers of flicker lines having nonequal intervals.
20. The method for detecting flicker noise according to claim 11 ,
wherein, in the case that the intervals between the flicker lines are not equal to each other, the number of flicker lines compared with the standard number is the number of the flicker lines having most frequent interval.
21. A non-transitory computer readable medium stored thereon computer executable instructions for performing a method, the method comprising:
an output step for outputting a standard data for flicker noise judgment using a statistical calculation value for each line where the statistical calculation values are calculated based on brightness information of pixels for each line of an object image;
a flicker line detection step for detecting flicker lines by identifying lines corresponding to the standard data where the distance between the lines are within a predetermined allowance of a regular interval; and
a judgment step for comparing the number of the detected flicker lines with a standard number for flicker noise judgment to judge if the object image is a flicker noise image,
wherein the output step include a first output step for outputting a first data for each line of the object image, where the first data is a statistical calculation value of brightness information of pixels corresponding to one line in the object image, and a filtering step for low-pass filtering the first data for each line,
wherein the standard number corresponds to 60% or more of a value obtained by dividing a height of the object image by a size of an interval between flicker lines.