Title of Invention

"AN APPARATUS FOR RETRIEVING AN IMAGE TEXTURE DESCRIPTOR FOR DESCRIBING TEXTURE FEATURES OF AN IMAGE"

Abstract A method for retrieving an image texture descriptor for describing texture feature of an image, including the steps of (a) filtering input images using predetermined filters having different orientation coefficients;(b) summing up and normalizing the pixel values of the filtered images onto axes of each predetermined direction to obtain data groups consisting of average of directional pixel values; (c) selecting candidate data groups among the data groups by a predetermined classification method; (d) determining a plurality of indicators based on orientation coefficients of the filters used in filtering the candidate data groups; and (e) determining the plurality of indicators as the texture descriptor of the image.
Full Text Technical Field
The present invention relates to a mothod and apparatus for retrieving an image texture descriptor for describing fesefute feature of an image.
Background Art
Recently, image texture has emerged as important visual features for searching and browsing a large set of similar image patterns. For example, a conventional texture descriptor for filtering a texture descriptor by a Gabor filter extracts a texture descriptor consisting of coefficients obtained by Gabor filtering. However, although conventional image texture descriptors consist of numerous vectors, it is quite difficult to visually perceive texture structures from the texture descriptor.
Disclosure of the Invention
It is an object of the present invention to provide a method for retrieving an image texture descriptor which can perceptually capture the texture structures present in an image.
It is another object of the present invention to provide a computer readable storage medium having a computer program stored therein, the program being arranged such that a computer executes the image texture descriptor retrieving method.
It is still another object of the present invention to provide an image texture descriptor retrieving apparatus which performs the image texture descriptor retrieving method.
To achieve the above object, there is provided a method for retrieving an image texture descriptor for describing texture features of an image, including the steps of (a) filtering input images using predetermined filters having different orientation coefficients, (b) projecting the filtered images onto axes of each predetermined direction to obtain data groups consisting of averages of each directional pixel values, (c) selecting candidate data groups among the data groups by a predetermined classification method, (d) determining a plurality of indicators based on orientation coefficients of the filters used in filtering the candidate data groups, and (e) determining the plurality of indicators as the texture descriptor of the image.
The step (a) may further include the step of (a-1) filtering input images using predetermined filters having different scale coefficients, and the step (d) further comprises the step of (d-1) determining a plurality of indicators based on scale coefficients of the filters used in filtering the candidate data groups.
The image texture descriptor retrieving method may further include the step of determining another indicator based on the presence of data groups filtered by filters having scale coefficients or orientation coefficients which are close to or identical with the scale coefficients or orientation coefficients of the filters used in filtering the selected candidate data groups.
The image texture descriptor retrieving method may further include the step of calculating the mean and variance of pixels with respect to the filtered images, and obtaining a predetermined vector using the calculated mean and variance.
According to another aspect of the present invention, there is provide a method for retrieving an image texture descriptor for describing texture features of an image, includes the steps of (a) filtering input images using predetermined filters having different scale coefficients, (b) projecting the filtered images onto axes of each predetermined direction to obtain data groups consisting of averages of each directional pixel values, (c) determining a plurality of indicators based on scale coefficients of the filters used in filtering data groups selected among the data groups by a predetermined selection method, (d) determining the plurality of indicators as the texture descriptor of the image.
According to still another aspect of the present invention, there is provided method for retrieving an image texture descriptor for describing texture features of an image, comprising the steps of (a) filtering input images using predetermined filters having different orientation coefficients and different scale coefficients, (b) projecting the filtered images onto horizontal and vertical axes to obtain horizontal-axis projection graphs and vertical-axis projection graphs, (c) calculating normalized auto-correlation values for each graph, (d) obtaining local maximums and local minimum for each normalized auto-correlation value, at which the calculated normalized auto-correlation values forms a local peak and a local valley at a predetermined section, (e) defining the average of the local maximums and the average the local minimums as contrast, (f) selecting graphs in which the ratio of the standard deviation to the average of the local maximums is less than or equal to a predetermined threshold as first candidate graphs, (g) determining the type of the second candidate graphs according to the number of graphs filtered by the filters having scale coefficients or orientation coefficients which are close to or identical with the scale coefficients or orientation coefficients of the filters used in filtering the selected second candidate graphs, (h) counting the numbers of graphs belonging to the respective types of second candidate graphs and determining predetermined weights of each type of second candidate graphs, (i) calculating the sum of products of the counted numbers of graphs and the determined weights to determine the calculation result value as a first indicator constituting a texture descriptor, (j) determining the orientation coefficients and scale coefficients of the second candidate graphs having the biggest contrast as second through fifth indicators, and (k) determining indicators including the first indicator and the second through fifth indicators as the texture descriptors of the corresponding image.
f The image texture descriptor retrieving method may further include the step of calculating the mean and variance of pixels with respect to the filtered images, and , obtaining a predetermined vector using the calculated mean and variance, wherein the stepjjc) includes the step of determining indicators including the first indicator, the second through fifth indicators and the predetermined vector as the texture descriptors of the corresponding image.
The normalized auto-correlation, denoted by NAC(k), is preferably calculated by the following formula:
(Formula Removed)
wherein N is a predetermined positive integer, an input image consists of N*N pixels, a pixel position is represented by i, where i is a number from 1 to N, the projection graphs expressed by pixels of the pixel position i is represented by P(i) and A: is a number from 1 to N.
The contrast is determined as:
(Formula Removed)
wherein Pjnagn (i) and Vjnagn (i) are the local maximums and local minimums determined in the step (d).
In the step (f), the graphs satisfying the following formula are selected as first candidate graphs:
(Formula Removed)
wherein d and S are the average and standard deviation of the local maximums and a is a predetermined threshold.
The step (g) includes the sub-steps of (g-1) if there are one or more graphs having scale or orientation coefficients identical with those of a pertinent candidate graph and one or more graphs having scale or orientation coefficients close to those of the pertinent candidate graph, classifying the pertinent candidate graph as a first type graph, (g-2) if there are one or more graphs having scale or orientation coefficients identical with those of a pertinent candidate graph but there is no graph having scale or orientation coefficients close to those of the pertinent candidate
graph, classifying the pertinent candidate graph as a second type graph, and (g-3) if there is no graph having scale or orientation coefficients identical with or close to those of a pertinent candidate graph, classifying the pertinent candidate graph as a third type graph.
The step (h) includes the step of counting the number of graphs belonging to each of the first through third types of graphs and determining predetermined weights for each of the types of graphs.
After the step of (f), there may be further included the step of applying a predetermined clustering algorithm to the first candidate graphs to select second candidate graphs.
The predetermined clustering algorithm is preferably modified agglomerative clustering.
Preferably, in the step (j), the orientation coefficient of a graph having the biggest contrast, among the horizontal-axis projection graphs, is determined as a ' second indicator; the orientation coefficient of a graph having the biggest contrast, among the vertical-axis projection graphs, is determined as a second indicator; the scale coefficient of a graph having the biggest contrast, among the horizontal-axis projection graphs, is determined as a fourth indicator; and the scale coefficient of a graph having the biggest contrast, among the vertical-axis projection graphs, is determined as a fifth indicator.
The step (j) may include the step of determining indicators including the first indicator, the second through fifth indicators and the predetermined vector as the texture descriptors of the corresponding image.
The predetermined filters preferably include Gabor filters. To achieve the second object of the present invention, there is provided a computer readable medium having program codes executable by a computer to perform a method for an image texture descriptor for describing texture features of an image, the method including the steps of (a) filtering input images using predetermined filters having different orientation coefficients and different scale coefficients, (b) projecting the filtered images onto horizontal and vertical axes to obtain horizontal-axis projection graphs and vertical-axis projection graphs, (c)
calculating normalized auto-correlation values for each graph, (d) obtaining local maximums and local minimums for each of normalized auto-correlation values, at which the calculated normalized auto-correlation value forms a local peak and a local valley at a predetermined section, (e) defining the average of the local maximums and the average the local minimums as contrast, (f) selecting graphs in which the ratio of the standard deviation to the average of the local maximums is less than or equal to a predetermined threshold as first candidate graphs, (g) determining the type of the second candidate graphs according to the number of graphs filtered by the filters having scale coefficients or orientation coefficients which are close to or identical with the scale coefficients or orientation coefficients of the filters used in filtering the selected second candidate graphs, (h) counting the numbers of graphs belonging to the respective types of second candidate graphs and determining predetermined weights of each type of second candidate graph, (i) calculating the sum of products of the counted numbers of graphs and the determined weights to determine the calculation result value as a first indicator constituting a texture descriptor, (j) determining the orientation coefficients and scale coefficients of the second candidate graphs having the biggest contrast as second through fifth indicators, and (k) determining indicators including the first indicator and the second through fifth indicators as the texture descriptors of the corresponding image.
To achieve the third object of the present invention, there is provided an apparatus method for retrieving an image texture descriptor for describing texture features of an image, the apparatus including filtering mean for filtering input images using predetermined filters having different orientation coefficients, projecting means for projecting the filtered images onto axes of each predetermined direction to obtain data groups consisting of averages of each directional pixel values, classifying means for selecting candidate data groups among the data groups by a predetermined classification method, first indicator determining means for determining another indicator based on the number of graphs filtered by filters having scale coefficients or orientation coefficients which are close to or identical with the scale coefficients ' or orientation coefficients of the filters used in filtering the selected candidate graph, and second indicator determining means for determining a plurality of indicators
based on scale coefficients and orientation coefficients of the filters used in filtering the determined candidate graphs.
Alternatively, there is provided an apparatus for retrieving an image texture descriptor for describing texture features of an image, the apparatus including a filtering unit for filtering input images using predetermined filters having different orientation coefficients and different scale coefficients, an image mean/variance calculating unit for calculating the mean and variance of pixels with respect to each of the filtered images, and obtaining a predetermined vector using the calculated mean and variance, a projecting unit for projecting the filtered images onto horizontal and vertical axes to obtain horizontal-axis projection graphs and vertical-axis projection graphs, a calculating unit for calculating a normalized auto-correlation value for each graph, a peak detecting/analyzing unit for detecting local maximums and local minimums for each auto-correlation value, at which the calculated normalized auto-correlation values forms a local peak and a local valley at a predetermined section, a mean/variance calculating unit for calculating the average of the local maximums and the average the local minimums, a first candidate graph selecting/storing unit for selecting the graphs satisfying the requirement that the ratio of the standard deviation to the average of the local maximums be less than or equal to a predetermined threshold, as first candidate graphs, a second candidate graph selecting/storing unit for applying a predetermined clustering algorithm to the first candidate graphs to select the same as second candidate graphs, a classifying unit for counting the number of graphs belonging to each of the respective types of the second candidate graphs, outputting data signals indicative of the number of graphs of each type, determining/predetermined weights of the graphs belonging to the respective types and ou/putting data signals indicative of weights to be applied to each type, a first indicator determining unit for calculating the sum of the products of the data representing the number of graphs belonging to each type, and the data representing the weights to be applied to each type, determining and outputting the calculation result as a first indicator constituting a texture descriptor, a contrast calculating unit for calculating the contrast according to formula (2) using the averages output from the mean/variance calculating unit and outputting a signal
indicating that the calculated contrast is biggest, a second candidate graph selecting/storing unit for outputting the candidate graphs having the biggest contrast among the second candidate graphs stored therein in response to the signal indicating that the calculated contrast is biggest, a second-to-fifth indicator determining unit for determining the orientation coefficient of a graph having the biggest contrast, among the horizontal-axis projection graphs; the orientation coefficient of a graph having the biggest contrast, among the vertical-axis projection graphs, as a second indicator; the scale coefficient of a graph having the biggest contrast, among the horizontal-axis projection graphs, as a fourth indicator; and the scale coefficient of a graph having the biggest contrast, among the vertical-axis projection graphs, as a fifth indicator, and a texture descriptor output unit for combining the first indicator, the second through fifth indicators and the predetermined vector and outputting the combination result as the texture descriptors of the corresponding image.
Accordingly, the present invention relates to an method of retrieving an image texture descriptor for describing texture features of an image characterized in that, said method comprising: (a) filtering input images using predetermined filters having different orientation coefficients; (b) summing up and normalizing the pixel values of the filtered images onto axes of each predetermined direction to obtain data groups "consisting of average of directional pixel values; (c) selecting candidate data groups among the data groups by a predetermined classification method; (d) determining a plurality of indicators based on orientation coefficients of the filters used in filtering the candidate data groups; and (e) determining the plurality of indicators as the texture descriptor of the image.
Brief Description of the Accompanying
The above objects and advantages of the present invention will become more apparent by describing in detail preferred embodiments thereof with reference to the attached drawings in which:
FIGS. 1A and IB are flow diagrams showing an image texture descriptor retrieving method according to the present invention;
FIG. 2 is a block diagram of an image texture descriptor retrieving apparatus according to the present invention; and
FIG. 3 shows perceptual browsing components (PBCs) extracted from Brodatz texture images by simulation based on the image texture descriptor retrieving method according to the present invention.
Best mode for carrying out the Invention
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
Referring to FIG. 1A showing an image texture descriptor retrieving method according to the present invention, assuming that N is a predetermined positive integer, an input image consisting of NxN pixels, for example, 128x128 pixels, is filtered using a Gabor filter (step 100). The Gabor filter is constituted by filters having different orientation coefficients and different scale coefficients. Assuming that C1 and C2 are predetermined positive integers, the input image is filtered by filters having C1 kinds of orientation coefficients and C2 kinds of scale coefficients, and the filters output C1xC2 kinds of filtered images.
Next, the mean and variance of pixels are calculated for each of the C1xC2 kinds of filtered images, and then a vector Z is obtained using the mean and variance (step 102).
Then, the filtered images are projected onto x- and y-axes to obtain x-projection graphs and y-projection graphs (step 104). The normalized autocorrelation (NAC) value for each graph P(i) (i is a number from 1 to N) denoted by NAC(k), is calculated by the following formula (1):
(Formula Removed)
wherein a pixel position is represented by i, the projection graphs expressed by pixels of the pixel position i are represented by P(i) and k is a number from 1 to N (N is a positive integer.).
Next, local maximums Pjnagn (i) and local minimums of Vmagn (/' ), at which the calculated NAC(k) forms a peak and a valley locally at a predetermined section, are obtained (step 108).
Now, contrast is defined as the following formula (2):
(Formula Removed)
(step 110).
Also, the graphs satisfying the following formula (3) are selected as first candidate graphs (step 112):
(Formula Removed)
wherein d and S are the average and standard deviation of the local maximums Pmagni (i) and or is a predetermined threshold.
Referring to FIG. IB, modified agglomerative clustering is applied to the first candidate graphs to select second candidate graphs (step 114). A modified agglomerative clustering algorithm is an appropriately modified algorithm of agglomerative clustering disclosed by R.O. Duda and P.E. Hart in "Pattern Classification and Scene Analysis, John Wiley and Sons, New York, 1973," which will now be described briefly. First, in N graphs P,, ...., PN> let the mean and standard deviation of distances between peaks be d; and S,, and each graph have a two-dimensional vector corresponding to (dj, S). Now, P, is clustered using the two-dimensional vector corresponding to (d,, S) as follows. Assuming that the desired number of clusters is Mc, with respect to initial number of clusters N, each cluster
C, can be expressed such that C,={P1}, C2={P2} CN={PN}. If the number of
clusters is smaller than Mc, clustering is stopped. Next, two clusters C1 and C1 which are most distant from each other are obtained. If the distance between Cj and Cj is greater than a predetermined threshold, clustering is stopped. Otherwise, Cj and Cj are merged to remove one of the two clusters. This procedure is repeatedly performed until the number of clusters reaches a predetermined number. Then, among the clustered clusters, the cluster having the roost graphs is selected and graphs in the selected cluster are selected as candidate graphs.
Now, the second candidate graphs are classified into three types (step 116). The classification is performed according to the number of graphs filtered by a filter having scale or orientation coefficients which are close to or identical with those of a filter used for filtering the second candidate graphs. Hereinafter, for the convenience' sake of explanation, the graphs filtered by a filter having a certain scale coefficient or a constant orientation coefficient will be referred to as certain-scale-coefficient graphs or certain-orientation-coefficient graphs.
In more detail, first, in the case where there are one or more graphs having
scale or orientation coefficients identical with those of a pertinent candidate graph
and one or more graphs having scale or orientation coefficients close to those of the
pertinent candidate graph, the pertinent candidate graph is classified as a CI type
graph. Second, in the case where there are one or more graphs having scale or
orientation coefficients identical with those of a pertinent candidate graph but there
is no graph having scale or orientation coefficients close to those of the pertinent
candidate graph, the pertinent candidate graph is classified as a C2 type graph.
Third, in the case where there is no graph having scale or orientation coefficients
identical with or close to those of a pertinent candidate graph, the pertinent candidate
graph is classified as a C3 type graph. Then, the numbers of graphs belonging to
each of the CI, C2 and C3 types are counted to be denoted by N,, N2 and N,,
respectively, and the respective weights of the graphs belonging to each of the CI,
C2 and C3 types are counted to be denoted by W,, W2 and W3, respectively, which
' will be described below.
Now, using the determined numbers N1,, N2 and N3, and the weights W,, W, and W3, the following calculation is performed:
(Formula Removed)
wherein the result M is determined as a first indicator V, constituting a texture descriptor (step 118).
With respect to the second candidate graphs, the orientation coefficients and scale coefficients of graphs that have the biggest contrast are determined as second through fifth indicators (step 120). In more detail, the orientation coefficient of a graph having the biggest contrast, among the x-projection graphs, is determined as a second indicator V2. Also, the orientation coefficient of a graph having the biggest contrast, among the y-projection graphs, is determined as a third indicator Vv The scale coefficient of a gjaph having the biggest contrast, among the x-projection graphs, is determined as a fourth indicator V4. Also, the scale coefficient of a graph having the biggest contrast, among the y-projectiori graphs, is determined as a fifth
indicator V5.
Using the first indicator V1 determined in the step 118, the second through fifth indicators V2, V3, V4 and V5, and the vector Z determined in the step 102, the texture descriptor, that is, the texture feature vector, is set to {[Vl, V2, V3, V4, Vs], Z} (step 122).
A large first indicator V1, indicates a high level of structuredness of the texture of an image. It has been experimentally confirmed that the first indicator V1, represents quite well the structuredness of the texture of an image. The second and third indicators V2 and V3 represent two quantized orientations in which the structuredness is captured most. The fourth and fifth indicators V4 and V5 represent two quantized scales in which the structuredness is captured most.
The texture descriptor is used as an index of an image in browsing or searching-retrieval applications. Especially, the image texture descriptor retrieved by the image texture descriptor retrieving method according to the present invention is suitably used in checker marks in which browsing patterns are regular, or structure oriented browsing, i.e., or embroidery patterns. Thus, in searching structurally similar patterns, image searching which is more adaptable to eye-perception is allowed by applying the image texture descriptor retrieving method according to the present invention to the applications based on the structured oriented browsing. Therefore, among indicators constituting texture descriptors retrieved by the image texture descriptor retrieving method according to the present invention, the first through fifth indicators V1, V2, V3, V4 and V5 can be referred to as perceptual browsing components (PBCs).
Also, with respect to each filtered image, the mean and variance of pixel values are calculated. The vector Z obtained by using the mean and variance can be referred to as similarity retrieval components (SRCs).
In other words, in the image texture descriptor retrieving method according to the present invention, the texture descriptor allows kinds of texture structures present in an image to be perceptually captured.
It has been described that a first indicator V1, which is a quite a good indicator of the structuredness of the texture of an image, second and third indicators V2 and
V3 representing two quantized orientations in which the structuredness is captured most, fourth and fifth indicators V4 and V5 representing two quantized scales in which the structuredness is captured most, are used as the texture descriptors of the image. However, the above-described embodiment is used in a descriptive sense only and not for the purpose of limitation. A single indicator that is most suitable to the characteristics of an image and arbitrarily selected plural indicators, can also be used as the texture descriptor(s) of the image. Therefore, the above-described embodiment is not intended as a restriction on the scope of the invention.
Also, the image texture descriptor retrieving method is programmable by a computer program. Codes and code segments constituting the computer program can be easily derived by a computer programmer in the art. Also, the program is stored in computer readable media and is readable and executable by the computer, thereby embodying the image texture descriptor retrieving method. The media include magnetic recording media, optical recording media, carrier wave media, and the like. Also, the image texture descriptor retrieving method can be embodied by an image texture descriptor retrieving apparatus. FIG. 2 is a block diagram of an image texture descriptor retrieving apparatus according to the present invention. Referring to FIG. 2, the image texture descriptor retrieving apparatus includes a Gabor filer 200, an image mean/variance calculating unit 202, an x-axis projector 204, a y-axis projector 205, an NAC calculating unit 206 and a peak detecting/analyzing unit 208. Also, the image texture descriptor retrieving apparatus includes a mean/variance calculating unit 210, a first candidate graph selecting/storing unit 212, a second candidate graph selecting/storing unit 214, a classifying unit 216, a first indicator determining unit 218, a contrast calculating unit 220, a second-to-fifth indicator determining unit 222 and a texture descriptor output unit 224.
In the operation of the image texture descriptor retrieving apparatus, assuming that N is a predetermined positive integer, the Gabor filter 200 filters an input image consisting of N*N pixels, for example, 128x128 pixels using filters (not shown) having different orientation coefficients and different scale coefficients, and outputs filtered images (imagefiltered). Assuming that CI and C2 are predetermined positive integers, the input image is filtered by filters having CI kinds of orientation
coefficients and C2 kinds of scale coefficients, and the filters output CI xC2 kinds of filtered images.
The image mean/variance calculating unit 202 calculates the mean and variance of pixels for each of the C1xC2 kinds of filtered images, to then obtain a vector Z using the mean and variance and outputs the obtained vector Z.
The x-axis projector 204 and the y-axis projector 205 project the filtered images onto x- and y-axes to obtain x-projection graphs and y-projection graphs. In other words, suppose a pixel position is represented by i (i is a number from 1 to N), the x-axis projector 204 and the y-axis projector 205 output the projection graphs P(i) expressed by pixels of the pixel position i (i-1,..., N).
The NAC calculating unit 206 calculates the normalized auto-correlation (NAC) value for each graph P(i), denoted by NAC(k), using the formula (1).
The peak detecting/analyzing unit 208 detects local maximums Pjnagn (i) and local minimums of Vjnagn (i), at which the calculated NAC(k) forms a local peak and a local valley at a predetermined section.
The mean/variance calculating unit 210 calculates the mean d and standard deviation S of the local maximums Pjnagn (i) and outputs the same. The first candidate graph selecting/storing unit 212 receives the mean d and standard deviation 5, selects the graphs satisfying the formula (3) as first candidate graphs (IstCAND) and stores the selected first candidate graphs, in which a is a predetermined threshold.
The second candidate graph selecting/storing unit 214 applies modified agglomerative clustering to the first candidate graphs to select the same as second candidate graphs (2nd_CAND).
The classifying unit 216, as described with reference to FIG. IB, counts the numbers of graphs belonging to each of the CI, C2 and C3 types to denote the same ty N1, N2 and N3, respectively, with respect to the second candidate graphs, and outputs data signals N, indicative of the number of graphs of each type. Also, the classifying unit 216 determines predetermined weights of the graphs belonging to each of the C1, C2 and C3 types to then denote the same by W,, Wz and W3, respectively, and outputs data signals W, indicative of weights to be applied to each
type.
The first indicator determining unit 218 calculates M as represented by the formula (4) using the determined numbers N,, N2 and N3, and the weights W,, W2 and W3, and determines and outputs the calculation result as a first indicator V, constituting a texture descriptor.
The contrast calculating unit 220 calculates the contrast by the formula (2) and outputs a signal Contmax indicating that the calculated contrast is biggest.
The second candidate graph selecting/storing unit 214 outputs the candidate graphs having the biggest contrast among the second candidate graphs stored therein to the second-to-fifth indicator determining unit 222.
The second-to-fifth indicator determining unit 222 determines the orientation coefficients and scale coefficients of graphs that have the biggest contrast as second through fifth indicators. In other words, the orientation coefficient of a graph having the biggest contrast, among the x-projection graphs, is determined as a second indicator V2. Also, the orientation coefficient of a graph having the biggest contrast, among the y-projection graphs, is determined as a second indicator V3. The scale coefficient of a graph having the biggest contrast, among the x-projection graphs, is determined as a fourth indicator V4. Also, the scale coefficient of a graph having the biggest contrast, among the y-projection graphs, is determined as a fifth indicator V5. The texture descriptor output unit 224 sets and outputs the texture descriptor, that is, the texture feature vector, as {[V1 V2, V3, V4, V5], Z}, using the first indicator V, output from the first indicator determining unit 218, the second through fifth indicators V2, V3, V4 and V5 output from the second-to-fifth indicator determining unit 222 and the vector Z output from the image mean/variance calculating unit 202.
FIG. 3 shows perceptual browsing components (PBCs) extracted from Brodatz texture images by simulation based on the image texture descriptor retrieving method according to the present invention.
As described above, according to the image texture descriptor retrieving method of the present invention, texture descriptors which allow kinds of texture structure present in an image to be perceptually captured can be retrieved.
Industrial Applicability
The present invention can be applied to the fields of image browsing or searching-retrieval applications.










We claim:
1. A method of retrieving an image texture descriptor for describing texture features
of an image characterized in that, said method comprising:
(a) filtering input images using predetermined filters having different orientation coefficients;
(b) summing up and normalizing the pixel values of the filtered images onto axes of each predetermined direction to obtain data groups consisting of average of directional pixel values;
(c) selecting candidate data groups among the data groups by a predetermined classification method;
(d) determining a plurality of indicators based on orientation coefficients of the filters used in filtering the candidate data groups; and
(e) determining the plurality of indicators as the texture descriptor of the image.

2. The method as claimed in claim 1, wherein the (a) further comprises (a-1) filtering input images using predetermined filters having different scale coefficients, and the (d) further comprises (d-1) determining a plurality of indicators based on scale coefficients of the filters used in filtering the candidate data groups.
3. The method as claimed in claim 2, further comprising (f) determining another indicator based on the presence of data groups filtered by filters having scale coefficients or orientation coefficients which are close to or identical with the scale coefficients or orientation coefficients of the filters used in filtering the selected candidate data groups.
4. The method as claimed in claim 3, further comprising (g) calculating the mean and variance of pixels with respect to each of the filtered images, and obtaining a predetermined vector using the calculated mean and variance.
5. An apparatus for performing the method of retrieving an image texture descriptor
for describing texture features of an image as claimed in claim 1, said apparatus
comprising:
a generating unit to generate regularity indicator indicating regularity of the image, direction indicator indicating direction of the image, and scale indicator indicating scale of the texture element of the image; and
an expressing unit for expressing a texture descriptor of the image using the regular indicator, the direction indicator and the scale indicator.
6. The apparatus as claimed in claim 5, wherein the generating unit generates the regularity indicator expressing the regularity of the image as one of a plurality of predetermined values.
7. The apparatus as claimed in claim 5, wherein the generating unit generates the regularity indicator expressing the regularity of the image as one of the values, "irregular", "slightly irregular", "regular" and "highly regular".
8. The apparatus as claimed in claim 5, wherein the generating unit generates the regularity indicator which is quantized integer.
9. The apparatus as claimed in claim 5, wherein the generating unit generates the direction indicator expressing the direction as one of a plurality of predetermined values.
10. The apparatus as claimed in claim 5, wherein the generating unit generates the direction indicator expressing the direction as one of the values, "no directionality", "0 degree", "30 degree", "60 degree", "90 degree", "120 degree" and "150 degree".
11. The apparatus as claimed in claim 5, wherein the generating unit generates the direction indicator which is quantized integer.
12. The apparatus as claimed in claim 5, wherein the generating unit generates the scale indicator expressing the scale as one of a plurality of predetermined values.
13. The apparatus as claimed in claim 5, wherein the generating unit generates the scale indicator expressing the scale as one of the values, "fine", "medium", "coarse" and "very coarse".
14. The apparatus as claimed in claim 5, wherein the generating unit generates the scale indicator which is quantized integer.
15. The apparatus as claimed in claim 5, wherein the expressing unit expressing the texture descriptor of the image as a vector, (the regular indicator, the direction indicator, the scale indicator).
16. The apparatus as claimed in claim 5, wherein the generating unit generates the direction indicator featuring dominant direction of the image.
17. The apparatus as claimed in claim 5, wherein the generating unit generates the scale indicator featuring scale corresponding to the dominant direction of the image.
18. The apparatus as claimed in claim 5, wherein the generating unit generates a first direction indicator and a second direction indicator featuring a first dominant direction of the image and a second dominant direction of the image, respectively.
19. The apparatus as claimed in claim 18, wherein the generating unit generates a first scale indicator featuring scale corresponding to the first dominant direction of the image and a second scale indicator featuring scale corresponding to the second dominant direction of the image.
20. The apparatus as claimed in claim 19, wherein the generating unit generates the texture descriptor of the image as a vector, (the regular indicator, the first
direction indicator, the second direction indicator, the first scale indicator, the second scale indicator).
21. A Method and Apparatus for describing texture features of an image substantially
as herein described with reference to the accompanying drawings.


Documents:

1344-delnp-2004-abstract.pdf

1344-delnp-2004-claims.pdf

1344-delnp-2004-correspondence-others.pdf

1344-delnp-2004-correspondence-po.pdf

1344-delnp-2004-description (complete).pdf

1344-delnp-2004-drawings.pdf

1344-delnp-2004-form-1.pdf

1344-delnp-2004-form-13.pdf

1344-delnp-2004-form-19.pdf

1344-delnp-2004-form-2.pdf

1344-delnp-2004-form-26.pdf

1344-delnp-2004-form-3.pdf

1344-delnp-2004-form-4.pdf

1344-delnp-2004-form-5.pdf

1344-delnp-2004-petition-137.pdf

1344-delnp-2004-petition-138.pdf


Patent Number 246082
Indian Patent Application Number 1344/DELNP/2004
PG Journal Number 07/2011
Publication Date 18-Feb-2011
Grant Date 14-Feb-2011
Date of Filing 18-May-2004
Name of Patentee THE REGENTS OF THE UNIVERSITY OF CALIFORNIA, an University in USA
Applicant Address 1111 FRANKLIN STREET, TWELFTH FLOOR, OAKLAND, CALIFORNIA 94607-5200, USA
Inventors:
# Inventor's Name Inventor's Address
1 Hyun-Doo Shin 510-1302 MUJIGAE MAEUL CHEONGGU APT., 221 KUMI-DONG BUNDANG-GU SUNGANAM-CITY KYUNGKI-DO 463-500 KOREA.
2 Yang-lim Choi 102-1112 WOOMAN SUNKYUNG APT., 105 WOOMAN-DONG PALDAL-GU, KYUNGKI-DO, 442-190 KOREA.
3 Peng Wu DEPARTMENT OF ELECTRICAL OF ELECTRICAL AND COMPUTER ENGINEERING, UNIVERSITY OF CALIFORNIA, SANTA BARBARA, CA 93106-9560 USA.
4 B.S. Manjunath DEPARTMENT OF ELECTRICAL AND COMPUTER ENGINEERING, UNIVERSITY OF CALIFORNIA, SANTA BARBARA, CA 93106-9560, USA.
PCT International Classification Number G06T 7/40
PCT International Application Number PCT/KR00/00091
PCT International Filing date 2000-02-03
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 PCT/KR00/00091 2000-02-03 PCT