Methods and systems for detecting cracks in illuminated electronic device screens
Systems and methods for detecting the cracks in illuminated electronic device screens are disclosed. In one embodiment, the method includes receiving an image of an electronic device screen and retrieving a plurality of kernels, each having values corresponding to a line region and a non-line region, with the orientation of the line region and the non-line region differing for each kernel. At least some of the kernels are applied to the image to obtain, at various locations of the image, values corresponding to the line regions and the non-line regions. Based on the values corresponding to the line regions and the non-line regions, cracks are automatically identified in the electronic device screen.
1 . A method performed by one or more computing devices for detecting cracks in a screen of an electronic device, the method comprising:
overlaying at least one kernel on an image of the screen of the electronic device at a selected location, the at least one kernel comprising a matrix having a line region and a non-line region;
determining a first average brightness value for the line region and a second average brightness value for the non-line region, wherein the non-line region comprises a first non-line region portion positioned on a first side of the line region and a second non-line region portion positioned on a second side of the line region opposite the first side; and
automatically identifying a crack at the selected location if the first average brightness value is greater than the second average brightness value by at least a predetermined threshold amount.
2 . The method of claim 1 , further comprising:
generating an image pyramid with multiple layers of the image, each of the multiple layers being down sampled to a different degree; and
for each of the multiple layers, overlaying the at least one kernel on the layer to obtain, at various locations of the layer, average brightness values for each of the line region and the non-line region.
3 . The method of claim 1 wherein the at least one kernel includes at least a first kernel and a second kernel, the second kernel comprising a matrix having a line region and a non-line region, wherein the line region in the first kernel has a first orientation, and wherein the line region in the second kernel has a second orientation different from the first orientation.
4 . The method of claim 1 wherein the line region comprises a first line region portion and a second line region portion, and wherein the method further comprises:
determining brightness values for each of the first line region portion and the second line region portion, wherein the first average brightness value for the line region is an average of the brightness value for the first line region portion and the brightness value for the second line region portion.
5 . The method of claim 1 wherein the image of the screen is a processed image, and wherein the method further comprises forming the processed image.
6 . The method of claim 1 , further comprising performing a secondary check on the identified crack to detect a false-positive crack identification.
7 . The method of claim 6 wherein the line region comprises a first line region portion and a second line region portion, and wherein the secondary check includes determining whether at least one of the following conditions is satisfied:
(a) a brightness value of the first non-line region portion and a brightness value of the second non-line region portion are within a predetermined range of one another;
(b) the brightness value of the first non-line region portion or the brightness value of the second non-line region portion is below a predetermined threshold level;
(c) the first average brightness value of the line region is greater than the second average brightness value of the non-line region by a predetermined threshold amount;
(d) any brightness value in the first line region portion, the second line region portion, the first non-line region portion, or the second non-line region portion is greater than a predetermined threshold value;
(e) any brightness value in the first line region portion, the second line region portion, the first non-line region portion, or the second non-line region portion is lower than a predetermined threshold value; and
(f) any three consecutive brightness values in the line region do not increase or decrease monotonically,
wherein, if any of conditions (a)-(f) are satisfied, then the identified crack is determined to be a false-positive crack identification.
8 . The method of claim 1 wherein overlaying the at least one kernel on the image of the screen of the electronic device includes overlaying the at least one kernel on an image of an illuminated mobile phone screen.
9 . A method performed by one or more computing devices for detecting cracks in a screen of an electronic device, the method comprising:
forming a processed image of the screen of the electronic device, wherein forming the processed image includes:
obtaining a lighted image of the screen;
obtaining a non-lighted image of the screen; and
subtracting the lighted image from the non-lighted image;
overlaying at least one kernel on the processed image at a selected location, the at least one kernel comprising a matrix having a line region and a non-line region;
determining a first average brightness value for the line region and a second average brightness value for the non-line region; and
automatically identifying a crack at the selected location if the first average brightness value is greater than the second average brightness value by at least a predetermined threshold amount.
10 . The method of claim 9 wherein the non-line region comprises a first non-line region portion and a second non-line region portion, and wherein the method further comprises:
determining brightness values for each of the first non-line region portion and the second non-line region portion, wherein the second average brightness value for the non-line region is an average of the brightness value for the first non-line region portion and the brightness value for the second non-line region portion.
11 . The method of claim 9 wherein the at least one kernel is a plurality of kernels, and wherein if a crack is identified at the selected location for any one of the plurality of kernels, any remaining kernels in the plurality of kernels are not overlayed on the processed image of the screen of the electronic device at the selected location.
12 . The method of claim 9 wherein the selected location is a first selected location, and wherein the method further comprises:
overlaying the at least one kernel on the processed image at a second selected location;
determining a third average brightness value for the line region and a fourth average brightness value for the non-line region at the second selected location; and
automatically identifying a crack at the second selected location if the third average brightness value is greater than the fourth average brightness value by at least the predetermined threshold amount.
13 . One or more computing systems for assessing a condition of an electronic device, the one or more computing systems comprising:
one or more processors for executing computer-executable instructions; and
a non-transitory computer-readable storage medium storing computer-executable instructions for execution by the one or more processors, wherein execution of the computer-executable instructions causes the one or more processors to:
obtain an image of the electronic device;
check for cracks in the electronic device outside of a screen region of the image, wherein, if one or more cracks outside of the screen region are identified, the electronic device is identified as damaged; and
after checking for cracks in the electronic device outside of the screen region:
overlay at least one kernel on the screen region of the image at a selected location of the screen region of the image, the at least one kernel comprising a matrix having a first region and a second region;
determine a first average brightness value for the first region and a second average brightness value for the second region; and
automatically identify a screen crack at the selected location if the first average brightness value is greater than the second average brightness value by at least a predetermined threshold amount.
14 . The one or more computing systems of claim 13 wherein execution of the computer-executable instructions further causes the one or more processors to:
generate multiple copies of the image, each of the copies being down sampled to a different degree; and
for each of the copies, overlay the at least one kernel on the copy to obtain the first average brightness value and the second average brightness value for the first and second regions.
15 . The one or more computing systems of claim 13 wherein the first region comprises a first portion and a second portion, and wherein execution of the computer-executable instructions further causes the one or more processors to:
determine brightness values for each of the first portion and the second portion, wherein the first average brightness value for the first region is an average of the brightness value for the first portion and the brightness value for second portion.
16 . The one or more computing systems of claim 15 wherein checking for cracks on the electronic device outside of the screen region of the image includes using at least one of a Canny edge detector and a Hough transform.
17 . The one or more computing systems of claim 13 wherein execution of the computer-executable instructions further causes the one or more processors to perform a secondary inspection of the identified screen crack to detect a false-positive crack identification.
18 . The one or more computing systems of claim 13 wherein the at least one kernel is a plurality of kernels, and wherein if a screen crack is identified at the selected location for any one of the plurality of kernels the computer-executable instructions further control the one or more computing systems to not overlay any additional kernels on the screen region of the image at the selected location.
19 . The one or more computing systems of claim 13 wherein the image of the electronic device is a processed image that includes at least a portion of a screen of the electronic device, and wherein execution of the computer-executable instructions further causes the one or more processors to generate the processed image, wherein generating the processed image includes:
obtaining a lighted image of the screen region;
obtaining a non-lighted image of the screen region; and
subtracting the lighted image from the non-lighted image.
20 . The one or more computing systems of claim 13 wherein the second region comprises a first portion positioned on a first side of the first region and a second portion positioned on a second side of the first region opposite the first side.