{"id":4524,"date":"2020-02-24T17:03:29","date_gmt":"2020-02-24T08:03:29","guid":{"rendered":"http:\/\/www.ide.titech.ac.jp\/ja\/?p=4524"},"modified":"2020-03-09T09:23:24","modified_gmt":"2020-03-09T00:23:24","slug":"doctorpresentation202003","status":"publish","type":"post","link":"http:\/\/www.ide.titech.ac.jp\/ja\/2020\/doctorpresentation202003","title":{"rendered":"\u535a\u58eb\u8ad6\u6587\u767a\u8868\u4f1a"},"content":{"rendered":"<p>\u8ad6\u6587\u767a\u8868\u4f1a\u958b\u50ac<br \/>\n\u65e5\u3000\u3000\u6642:\u4ee4\u548c2\u5e743\u670816\u65e5(\u6708)9:00\uff5e10:30<br \/>\n\u4f1a\u3000\u3000\u5834:\u77f3\u5ddd\u53f04\u53f7\u9928\u5730\u968e\u4f1a\u8b70\u5ba4(B04\/05\u53f7\u5ba4)<br \/>\n\u53f8\u4f1a\u6559\u54e1:\u5c71\u4e0b\u5e78\u5f66\u6559\u6388<\/p>\n<p>\u6c0f\u3000\u3000\u540d:\u30c1\u30e7\u30a6\u3000\u30ab\u30c4\u30b7<\/p>\n<p>\u8ad6\u6587\u984c\u76ee<\/p>\n<p>\u300cCriterion for image matching with global projection transformation<br \/>\ncorrelation and its acceleration algorithms\uff08\u5927\u5c40\u7684\u5c04\u5f71\u5909\u63db\u76f8\u95a2\u306b\u3088\u308b\u753b\u50cf\u30de\u30c3\u30c1<br \/>\n\u30f3\u30b0\u306e\u305f\u3081\u306e\u8a55\u4fa1\u57fa\u6e96\u304a\u3088\u3073\u305d\u306e\u9ad8\u901f\u8a08\u7b97\uff09\u300d<\/p>\n<p>\u6982\u8981<\/p>\n<p>Image matching is a strong ally in computer vision field, because it outputs<br \/>\nthe correspondence between the input images and templates. The most important<br \/>\nthing in image matching is the invariant matching result against adverse<br \/>\nconditions such as noise, color of background, geometrical transformations,<br \/>\netc. Furthermore, short calculation time is also highly expected for real-world<br \/>\napplications. This thesis proposes a theoretical criterion of GPT (Global<br \/>\nProjection Transformation) correlation matching which revises the deformations<br \/>\nbetween input images and templates by 2D projection transformation. In the<br \/>\nthesis, we also discuss the local features and acceleration algorithm to<br \/>\nreinforce the stability of the proposed criterion and shorten the calculation<br \/>\ntime.<\/p>\n<p>GPT correlation matching technique is originated by Wakahara and Yamashita to<br \/>\nrealize a projection-invariant image matching technique. However, theoretically,<br \/>\nthere is a serious defect in the conventional criterion. So firstly, we<br \/>\nintroduce the conventional GPT correlation matching model and point out a<br \/>\nproblem that the conventional approach does not guarantee the conservation of<br \/>\nthe L2 norm of the transformed images. The problem will lead mismatches during<br \/>\nthe optimization of the criterion. To solve this problem the theoretical<br \/>\ncriterion is proposed by introducing a norm normalization factor. Furthermore,<br \/>\nthe conventional GPT correlation matching realizes the 2D projection<br \/>\ntransformation by the alternative calculation of AT (Affine Transformation) and<br \/>\nPPT (Partial Projection Transformation), which causes the incompatibility during<br \/>\nthe matching process. This thesis also focuses on the norm normalization of the<br \/>\nsimultaneous calculation of AT and PPT. The mathematical derivation and<br \/>\nimplementation algorithm of the proposed criteria are described in detail and<br \/>\nsome demonstrations using toy image data are also illustrated. From the<br \/>\ndemonstrations, the proposed approach achieves not only higher correlations<br \/>\nbetween the input images and template, but also faster convergence speed.<\/p>\n<p>During the matching process, both the conventional approach and the proposed<br \/>\napproach use only the quantized gradient direction of the target pixel as a<br \/>\nkind of space filter to mitigate mismatches. However, in the field of natural<br \/>\nimage matching, the quantized gradient direction is greatly affected by<br \/>\ndeformations or distortion of the image. To achieve a more robust and stable<br \/>\nmatching against bad conditions of the images, this thesis also proposes some<br \/>\nkinds of local features of the histogram of oriented quantized gradient<br \/>\ndirection (HOG) information of a 5-by-5 block around each target pixel. For<br \/>\nexample, we simplify the HOG features by eliminating the non-significant<br \/>\ndirections. Or, we also perform k-means clustering to simplify the HOT features.<br \/>\nThe comparison among matching abilities using these HOG patterns is shown by<br \/>\ndemonstrations. From the demonstrations, in case the test images suffer from<br \/>\nlarge deformation, the matching results are stable with the assist of the local<br \/>\nfeatures, while the conventional space filter does not lead to the converge<br \/>\npoint any longer.<\/p>\n<p>Furthermore, the proposed criterion is expected to be utilized into real-world<br \/>\napplications, so short calculation time is highly required. This thesis<br \/>\nintroduces the acceleration algorithm of the proposed algorithm. The key idea<br \/>\nof the acceleration algorithm is to create two kinds of reference tables. These<br \/>\nreference tables can avoid the na\u00efve search of the image domain, which<br \/>\ndramatically reduce the calculation time to about one hundredth. Since the<br \/>\ncalculation time for creating the reference tables is still the fourth-order of<br \/>\nthe image size, an acceleration algorithm for creating the reference tables<br \/>\nusing integral images is also proposed. The same demonstrations as above-<br \/>\nmentioned section are conducted firstly to show the agreement of the matching<br \/>\nresults no matter the acceleration algorithm is used or not, and as well as the<br \/>\nsignificant reduction of the calculation time than the standard algorithm about<br \/>\none thousandth.<\/p>\n<p>Several experiments are performed to show the advantages of the proposed<br \/>\napproach. The experiments can be divided into two sections, one is the image<br \/>\nmatching part and the other is the image discrimination part. In image matching<br \/>\npart we perform &#8220;whole-to-whole&#8221; and &#8220;whole-to-part&#8221; template matchings using<br \/>\nnatural images from some famous datasets vis the conventional approaches, the<br \/>\nproposed approach as well as the acceleration algorithm, and the state-of-the-<br \/>\nart methods. In image discrimination part, the image discrimination of<br \/>\nhandwritten digit from MNIST database is performed vis the conventional<br \/>\napproaches and the accelerated proposed approach. The comparison of the<br \/>\ncorrelation values and the error rates output by these approaches are listed up.<\/p>\n<p>From the demonstrations and experiments, we can distinguish the outstanding<br \/>\nperformance of the proposed approach not only in image matching field but also<br \/>\nin image recognition field. It also has high potential to be applied to some<br \/>\nother real-world computer vision tasks.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u8ad6\u6587\u767a\u8868\u4f1a\u958b\u50ac \u65e5\u3000\u3000\u6642:\u4ee4\u548c2\u5e743\u670816\u65e5(\u6708)9:00\uff5e10:30 \u4f1a\u3000\u3000\u5834:\u77f3\u5ddd\u53f04\u53f7\u9928\u5730\u968e\u4f1a\u8b70\u5ba4(B04\/05\u53f7\u5ba4) \u53f8\u4f1a\u6559\u54e1:\u5c71\u4e0b\u5e78\u5f66\u6559\u6388 \u6c0f\u3000\u3000\u540d:\u30c1\u30e7\u30a6\u3000\u30ab\u30c4\u30b7 \u8ad6\u6587\u984c\u76ee \u300cCriterion for im [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[],"class_list":["post-4524","post","type-post","status-publish","format-standard","hentry","category-presentations"],"_links":{"self":[{"href":"http:\/\/www.ide.titech.ac.jp\/ja\/wp-json\/wp\/v2\/posts\/4524","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.ide.titech.ac.jp\/ja\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.ide.titech.ac.jp\/ja\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.ide.titech.ac.jp\/ja\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.ide.titech.ac.jp\/ja\/wp-json\/wp\/v2\/comments?post=4524"}],"version-history":[{"count":4,"href":"http:\/\/www.ide.titech.ac.jp\/ja\/wp-json\/wp\/v2\/posts\/4524\/revisions"}],"predecessor-version":[{"id":4529,"href":"http:\/\/www.ide.titech.ac.jp\/ja\/wp-json\/wp\/v2\/posts\/4524\/revisions\/4529"}],"wp:attachment":[{"href":"http:\/\/www.ide.titech.ac.jp\/ja\/wp-json\/wp\/v2\/media?parent=4524"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.ide.titech.ac.jp\/ja\/wp-json\/wp\/v2\/categories?post=4524"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.ide.titech.ac.jp\/ja\/wp-json\/wp\/v2\/tags?post=4524"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}