Method for evaluating skin tissue and system using the same

Patent metadata

Field	Value
Publication number	US-2017193659-A1
Application number	US-201615395258-A
Country	US
Kind code	A1
Filing date	Dec 30, 2016
Priority date	Jan 5, 2016
Publication date	Jul 6, 2017
Grant date	—

Abstract

A method for evaluating skin tissue includes: obtaining a tomographic image of skin; performing a quantization process for quantizing brightness values of the tomographic image of skin to generate a quantized image; performing a binarization process on the brightness value of each image point in the quantized image according to a first threshold interval to generate a first filtered image; performing the binarization process on the brightness value of each image point in the quantized image according to a second threshold interval to generate a second filtered image; obtaining a first estimated tissue boundary according to the distribution of the bright spots in the first filtered image; obtaining a second estimated tissue boundary according to the distribution of the bright spots in the second filtered image; estimating a thickness of skin tissue according to a difference between the first and second estimated tissue boundaries.

First claim

What is claimed is:

1 . A method for evaluating skin tissue, comprising:
obtaining a tomographic image of skin; performing a quantization process for quantizing brightness values of the tomographic image of skin into a plurality of brightness levels to generate a quantized image; performing a binarization process on the brightness value of each image point in the quantized image according to a first brightness threshold interval to generate a first filtered image, wherein in the quantized image, image points whose brightness values fall within the first brightness threshold interval are set as bright spots in the first filtered image, and image points whose brightness values fall outside the first brightness threshold interval are set as dark spots in the first filtered image; performing the binarization process on the brightness value of each image point in the quantized image according to a second brightness threshold interval to generate a second filtered image, wherein in the quantized image, image points whose brightness values fall within the second brightness threshold interval are set as bright spots in the second filtered image, and image points whose brightness values fall outside the second brightness threshold interval are set as dark spots in the second filtered image; obtaining a first estimated tissue boundary according to the distribution of the bright spots in the first filtered image; obtaining a second estimated tissue boundary according to the distribution of the bright spots in the second filtered image; and estimating a thickness of skin tissue according to a difference between the first and second estimated tissue boundaries.

2 . The method for evaluating skin tissue according to claim 1 , wherein the step of obtaining the first estimated tissue boundary further comprises:
performing a dilation and erosion process on the first filtered image to generate a repaired image, wherein the repaired image comprises a plurality of bright blocks formed of aggregated bright spots; and calculating an estimated top position of dermis as the first estimated tissue boundary according to an average height of the bright blocks at a top of the repaired image.

3 . The method for evaluating skin tissue according to claim 1 , wherein the step of obtaining the second estimated tissue boundary further comprises:
detecting heights of a plurality of bottom bright spots of the second filtered image, wherein each of the bottom bright spots in a corresponding image column of the second filtered image, unlike other bright spots in the corresponding image column, has a minimum height; and calculating the second estimated tissue boundary according to the heights of the plurality of bottom bright spots.

4 . The method for evaluating skin tissue according to claim 3 , further comprising:
determining whether the height of a first bottom bright spot of the plurality of bottom bright spots is larger than the first estimated tissue boundary; and adjusting the height of the first bottom bright spot to be smaller than the first estimated tissue boundary if it is determined that the height of the first bottom bright spot is larger than the first estimated tissue boundary.

5 . The method for evaluating skin tissue according to claim 3 , further comprising:
determining whether a height difference between a first bottom bright spot of the plurality of bottom bright spots and a second bottom bright spot of the plurality of bottom bright spots is larger than a height threshold, wherein the first bottom bright spot and the second bottom bright spot are respectively located at two adjacent image columns in the second filtered image; and determining whether a quantity of bright spots in a default segment above the first bottom bright spot in the image column is larger than a quantity threshold if it is determined that the height difference between the second bottom bright spot and the first bottom bright spot is larger than the height threshold; and adjusting the height of the first bottom bright spot to the height of the second bottom bright spots if it is determined that the quantity of bright spots in the default segment is smaller than the quantity threshold.

6 . The method for evaluating skin tissue according to claim 3 , further comprising:
generating the second estimated tissue boundary according to a weighting average of an average height, a maximum height and a minimum height of the bottom bright spots.

7 . The method for evaluating skin tissue according to claim 1 , further comprising:
performing the binarization process on the brightness value of each image point in the quantized image according to a third brightness threshold interval to generate a third filtered image, wherein in the quantized image, the image points whose brightness values fall within the third brightness threshold interval are set as bright spots in the third filtered image, and the image points whose brightness values fall outside the third brightness threshold interval are set as dark spots in the third filtered image; obtaining a third estimated tissue boundary according to the distribution of the bright spots in the third filtered image; and estimating another thickness of skin tissue according to a difference between the third estimated tissue boundary and the first estimated tissue boundary.

8 . The method for evaluating skin tissue according to claim 7 , wherein the step of obtaining the third estimated tissue boundary further comprises:
detecting heights of a plurality of top bright spots in the third filtered image, wherein each of the top bright spots in a corresponding image column of the third filtered image, unlike other bright spots in the corresponding image column, has a maximum height; and calculating the third estimated tissue boundary according to the heights of the top bright spots.

9 . The method for evaluating skin tissue according to claim 8 , further comprising:
determining whether a height difference between a first top bright spot of the plurality of top bright spots and a second top bright spot of the plurality of top bright spots is larger than a height threshold, wherein the first top bright spot and the second top bright spot are respectively located at two adjacent image columns in the third filtered image; and adjusting the height of the first top bright spot such that the height difference between the first top bright spot and the second top bright spot is smaller than the height threshold if it is determined that the height difference between the first top bright spot and the second top bright spot is larger than the height threshold.

10 . The method for evaluating skin tissue according to claim 9 , wherein the step of adjusting the height of the first top bright spot further comprises:
determining whether there are any bright spots existing within a default interval under the image column at which the first top bright spot is located; updating the first top bright spot as the bright spot having a maximum height in the default interval if it is determined that there are bright spots existing within the default interval; and adjusting the height of the first top bright spot to the height of the second top bright spot if it is determined that there are no bright spots existing within the default interval.

11 . The method for evaluating skin tissue according to claim 8 , further comprising:
generating the third estimated tissue boundary according to a weighting average of an average height, a maximum height and a minimum height of the top bright spots.

12 . The method for evaluating skin tissue according to claim 1 , further compri

Assignees

• Ind Tech Res Inst

Inventors

• Wang Yen-Chang
• Cheng Chih-Ming
• Chang Chir-Weei
• Chang Chi-Shen
• Chang Sheng-Li

Classifications

• G06T2207/30088

  Skin; Dermal · CPC title

• A61B5/441

  Skin evaluation, e.g. for skin disorder diagnosis · CPC title

• A61B8/0858

  involving measuring tissue layers, e.g. skin, interfaces · CPC title

• A61B5/0066

  Optical coherence imaging · CPC title

• G06T7/0012 Primary

  Biomedical image inspection · CPC title