{"id":997,"date":"2021-12-31T11:43:35","date_gmt":"2021-12-31T03:43:35","guid":{"rendered":"http:\/\/139.9.1.231\/?p=997"},"modified":"2022-08-29T16:31:45","modified_gmt":"2022-08-29T08:31:45","slug":"ssd","status":"publish","type":"post","link":"http:\/\/139.9.1.231\/index.php\/2021\/12\/31\/ssd\/","title":{"rendered":"SSD\u539f\u7406\u4e0e\u5b9e\u73b0"},"content":{"rendered":"\n<p>SSD\u5c5e\u4e8e\u4e00\u9636\u6bb5\u3001<strong>anchor-based&nbsp;\u76ee\u6807\u68c0\u6d4b<\/strong><\/p>\n\n\n\n<p>\u57fa\u4e8eanchor-based\u7684\u6280\u672f\u5305\u62ec\u4e00\u4e2a\u9636\u6bb5\u548c\u4e24\u4e2a\u9636\u6bb5\u7684\u68c0\u6d4b\u3002\u5176\u4e2d\u4e00\u9636\u6bb5\u7684\u68c0\u6d4b\u6280\u672f\u5305\u62ecSSD\uff0cDSSD\uff0cRetinaNet\uff0cRefineDet\uff0cYOLOV3\u7b49\uff0c\u4e8c\u9636\u6bb5\u6280\u672f\u5305\u62ecFaster-RCNN\uff0cR-FCN\uff0cFPN\uff0cCascade R-CNN\uff0cSNIP\u7b49\u3002\u4e00\u822c\u7684\uff0c\u4e24\u4e2a\u9636\u6bb5\u7684\u76ee\u6807\u68c0\u6d4b\u4f1a\u6bd4\u4e00\u4e2a\u9636\u6bb5\u7684\u7cbe\u5ea6\u8981\u9ad8\uff0c\u4f46\u4e00\u4e2a\u9636\u6bb5\u7684\u7b97\u6cd5\u901f\u5ea6\u4f1a\u66f4\u5feb\u3002<\/p>\n\n\n\n<p class=\"has-light-pink-background-color has-background\">&nbsp;<strong>anchor-based\u7c7b\u7b97\u6cd5\u4ee3\u8868\u662ffasterRCNN\u3001SSD\u3001YoloV2\/V3\u7b49<\/strong><\/p>\n\n\n\n<p>           \u76ee\u6807\u68c0\u6d4b\u8fd1\u5e74\u6765\u5df2\u7ecf\u53d6\u5f97\u4e86\u5f88\u91cd\u8981\u7684\u8fdb\u5c55\uff0c\u4e3b\u6d41\u7684\u7b97\u6cd5\u4e3b\u8981\u5206\u4e3a\u4e24\u4e2a\u7c7b\u578b\uff08\u53c2\u8003<a rel=\"noreferrer noopener\" href=\"https:\/\/arxiv.org\/pdf\/1711.06897.pdf\" target=\"_blank\">RefineDet<\/a>\uff09\uff1a\uff081\uff09<strong>two-stage\u65b9\u6cd5<\/strong>\uff0c\u5982R-CNN\u7cfb\u7b97\u6cd5\uff0c\u5176\u4e3b\u8981\u601d\u8def\u662f\u5148\u901a\u8fc7\u542f\u53d1\u5f0f\u65b9\u6cd5\uff08selective search\uff09\u6216\u8005CNN\u7f51\u7edc\uff08RPN)\u4ea7\u751f\u4e00\u7cfb\u5217\u7a00\u758f\u7684\u5019\u9009\u6846\uff0c\u7136\u540e\u5bf9\u8fd9\u4e9b\u5019\u9009\u6846\u8fdb\u884c\u5206\u7c7b\u4e0e\u56de\u5f52\uff0ctwo-stage\u65b9\u6cd5\u7684\u4f18\u52bf\u662f\u51c6\u786e\u5ea6\u9ad8\uff1b\uff082\uff09<strong>one-stage\u65b9\u6cd5<\/strong>\uff0c\u5982Yolo\u548cSSD\uff0c\u5176\u4e3b\u8981\u601d\u8def\u662f\u5747\u5300\u5730\u5728\u56fe\u7247\u7684\u4e0d\u540c\u4f4d\u7f6e\u8fdb\u884c\u5bc6\u96c6\u62bd\u6837\uff0c\u62bd\u6837\u65f6\u53ef\u4ee5\u91c7\u7528\u4e0d\u540c\u5c3a\u5ea6\u548c\u957f\u5bbd\u6bd4\uff0c\u7136\u540e\u5229\u7528CNN\u63d0\u53d6\u7279\u5f81\u540e\u76f4\u63a5\u8fdb\u884c\u5206\u7c7b\u4e0e\u56de\u5f52\uff0c\u6574\u4e2a\u8fc7\u7a0b\u53ea\u9700\u8981\u4e00\u6b65\uff0c\u6240\u4ee5\u5176\u4f18\u52bf\u662f\u901f\u5ea6\u5feb\uff0c\u4f46\u662f\u5747\u5300\u7684\u5bc6\u96c6\u91c7\u6837\u7684\u4e00\u4e2a\u91cd\u8981\u7f3a\u70b9\u662f\u8bad\u7ec3\u6bd4\u8f83\u56f0\u96be\uff0c\u8fd9\u4e3b\u8981\u662f\u56e0\u4e3a\u6b63\u6837\u672c\u4e0e\u8d1f\u6837\u672c\uff08\u80cc\u666f\uff09\u6781\u5176\u4e0d\u5747\u8861\uff08\u53c2\u89c1<a rel=\"noreferrer noopener\" href=\"https:\/\/arxiv.org\/abs\/1708.02002\" target=\"_blank\">Focal Loss<\/a>\uff09\uff0c\u5bfc\u81f4\u6a21\u578b\u51c6\u786e\u5ea6\u7a0d\u4f4e\u3002<\/p>\n\n\n\n<p class=\"has-light-gray-background-color has-background\"><strong>\u9700\u8981\u638c\u63e1\u7684\u77e5\u8bc6\uff1a<\/strong><\/p>\n\n\n\n<p class=\"has-light-pink-background-color has-background\"><strong>1\u3001\u8fb9\u754c\u6846<\/strong><\/p>\n\n\n\n<p>\u5728\u2f6c\u6807\u68c0\u6d4b\u4e2d\uff0c\u6211\u4eec\u901a\u5e38\u4f7f\u2f64\u8fb9\u754c\u6846\uff08bounding box\uff09\u6765\u63cf\u8ff0\u5bf9\u8c61\u7684\u7a7a\u95f4\u4f4d\u7f6e\u3002\u8fb9\u754c\u6846\u662f\u77e9\u5f62\u7684\uff0c\u7531\u77e9\u5f62\u5de6\u4e0a\u2ec6\u7684 x \u548c y \u5750\u6807\u4ee5\u53ca\u53f3\u4e0b\u2ec6\u7684\u5750\u6807\u51b3\u5b9a\u3002\u53e6\u2f00\u79cd\u5e38\u2f64\u7684\u8fb9\u754c\u6846\u8868\u2f70\u2f45\u6cd5\u662f\u8fb9\u754c\u6846\u4e2d\u2f3c\u7684 (x, y) \u8f74\u5750\u6807\u4ee5\u53ca\u6846\u7684\u5bbd\u5ea6\u548c\u2fbc\u5ea6<\/p>\n\n\n\n<p class=\"has-light-gray-background-color has-background\"><strong>2\u3001\u951a\u6846<\/strong><\/p>\n\n\n\n<p class=\"has-text-align-left has-light-pink-background-color has-background\">       \u2f6c\u6807\u68c0\u6d4b\u7b97\u6cd5\u901a\u5e38\u4f1a\u5728\u8f93\u2f0a\u56fe\u50cf\u4e2d\u91c7\u6837\u2f24\u91cf\u7684\u533a\u57df\uff0c\u7136\u540e\u5224\u65ad\u8fd9\u4e9b\u533a\u57df\u4e2d\u662f\u5426\u5305\u542b\u6211\u4eec\u611f\u5174\u8da3\u7684\u2f6c\u6807\uff0c\u5e76\u8c03\u6574\u533a\u57df\u8fb9\u7f18\u4ece\u800c\u66f4\u51c6\u786e\u5730\u9884\u6d4b\u2f6c\u6807\u7684\u771f\u5b9e\u8fb9\u754c\u6846\uff08ground-truth bounding box\uff09\u3002\u4e0d\u540c\u7684\u6a21\u578b\u4f7f\u2f64\u7684\u533a\u57df\u91c7\u6837\u2f45\u6cd5\u53ef\u80fd\u4e0d\u540c\u3002\u8fd9\u2fa5\u6211\u4eec\u4ecb\u7ecd\u5176\u4e2d\u7684\u2f00\u79cd\u2f45\u6cd5\uff1a\u5b83\u4ee5\u6bcf\u4e2a\u50cf\u7d20\u4e3a\u4e2d\u2f3c\u2f63\u6210\u591a\u4e2a\u2f24\u5c0f\u548c\u5bbd\u2fbc\u2f50\uff08aspect ratio\uff09\u4e0d\u540c\u7684\u8fb9\u754c\u6846\u3002\u8fd9\u4e9b\u8fb9\u754c\u6846\u88ab\u79f0\u4e3a\u951a\u6846\uff08anchor box\uff09<\/p>\n\n\n\n<p class=\"has-light-gray-background-color has-background\">3\u3001\u4ea4\u5e76\u2f50(IoU)<\/p>\n\n\n\n<p class=\"has-light-pink-background-color has-background\">\u76f4\u89c2\u5730\u8bf4\uff0c\u6211\u4eec\u53ef\u4ee5\u8861\u91cf\u951a\u6846\u548c\u771f\u5b9e\u8fb9\u754c\u6846\u4e4b\u95f4\u7684\u76f8\u4f3c\u6027\u3002\u6211\u4eec\u77e5\u9053 Jaccard \u7cfb\u6570\u53ef\u4ee5\u8861\u91cf<br>\u4e24\u7ec4\u4e4b\u95f4\u7684\u76f8\u4f3c\u6027\u3002\u7ed9\u5b9a\u96c6\u5408 A \u548c B\uff0c\u4ed6\u4eec\u7684 Jaccard \u7cfb\u6570\u662f\u4ed6\u4eec\u4ea4\u96c6\u7684\u2f24\u5c0f\u9664\u4ee5\u4ed6\u4eec\u5e76\u96c6\u7684\u2f24\u5c0f\uff1a$$J\\left( A,B\\right) =\\dfrac{\\left| A\\cap B\\right| }{\\left| A\\right| U\\left| B\\right| }$$ \u4e8b\u5b9e\u4e0a\uff0c\u6211\u4eec\u53ef\u4ee5\u5c06\u4efb\u4f55\u8fb9\u754c\u6846\u7684\u50cf\u7d20\u533a\u57df\u89c6\u4e3a\u2f00\u7ec4\u50cf\u7d20\u3002\u901a\u8fc7\u8fd9\u79cd\u2f45\u5f0f\uff0c\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7\u5176\u50cf\u7d20\u96c6\u7684 Jaccard\u7d22\u5f15\u6765\u6d4b\u91cf\u4e24\u4e2a\u8fb9\u754c\u6846\u7684\u76f8\u4f3c\u6027\u3002\u5bf9\u4e8e\u4e24\u4e2a\u8fb9\u754c\u6846\uff0c\u6211\u4eec\u901a\u5e38\u5c06\u4ed6\u4eec\u7684 Jaccard \u6307\u6570\u79f0\u4e3a \u4ea4\u5e76\u2f50 (intersectionover union\uff0cIoU)\uff0c\u5373\u4e24\u4e2a\u8fb9\u754c\u6846\u76f8\u4ea4\u2faf\u79ef\u4e0e\u76f8\u5e76\u2faf\u79ef\u4e4b\u2f50<\/p>\n\n\n\n<p class=\"has-light-gray-background-color has-background\">4\u3001\u6807\u6ce8\u8bad\u7ec3\u6570\u636e\u7684\u951a\u6846<\/p>\n\n\n\n<p class=\"has-light-pink-background-color has-background\">\u5728\u8bad\u7ec3\u96c6\u4e2d\uff0c\u6211\u4eec\u5c06\u6bcf\u4e2a\u951a\u6846\u89c6\u4e3a\u2f00\u4e2a\u8bad\u7ec3\u6837\u672c\u3002\u4e3a\u4e86\u8bad\u7ec3\u2f6c\u6807\u68c0\u6d4b\u6a21\u578b\uff0c\u6211\u4eec\u9700\u8981\u6bcf\u4e2a\u951a\u6846\u7684\u7c7b\u522b\uff08class\uff09\u548c\u504f\u79fb\u91cf\uff08offset\uff09\u6807\u7b7e\uff0c\u5176\u4e2d\u524d\u8005\u662f\u4e0e\u951a\u6846\u76f8\u5173\u7684\u5bf9\u8c61\u7684\u7c7b\u522b\uff0c\u540e\u8005\u662f\u771f\u5b9e\u8fb9\u754c\u6846\u76f8\u5bf9\u4e8e\u951a\u6846\u7684\u504f\u79fb\u91cf\u3002\u5728\u9884\u6d4b\u671f\u95f4\uff0c\u6211\u4eec\u4e3a\u6bcf\u4e2a\u56fe\u50cf\u2f63\u6210\u591a\u4e2a\u951a\u6846\uff0c\u9884\u6d4b\u6240\u6709\u951a\u6846\u7684\u7c7b\u548c\u504f\u79fb\u91cf\uff0c\u6839\u636e\u9884\u6d4b\u7684\u504f\u79fb\u91cf\u8c03\u6574\u5b83\u4eec\u7684\u4f4d\u7f6e\u4ee5\u83b7\u5f97\u9884\u6d4b\u7684\u8fb9\u754c\u6846\uff0c\u6700\u540e\u53ea\u8f93\u51fa\u7b26\u5408\u7279\u5b9a\u6761\u4ef6\u7684\u9884\u6d4b\u8fb9\u754c\u6846\u3002<\/p>\n\n\n\n<p class=\"has-light-gray-background-color has-background\">5\u3001\u5c06\u771f\u5b9e\u8fb9\u754c\u6846\u5206\u914d\u7ed9\u951a\u6846<\/p>\n\n\n\n<p class=\"has-light-pink-background-color has-background\">\u7ed9\u5b9a\u56fe\u50cf, \u5047\u8bbe\u951a\u6846\u662f  \\(A_{1}, A_{2}, \\ldots, A_{n_{a}}\\) , \u771f\u5b9e\u8fb9\u754c\u6846\u662f  \\(B_{1}, B_{2}, \\ldots, B_{n_{b}}\\) , \u5176\u4e2d  \\( n_{a} \\geq n_{b}\\) \u3002\u8ba9\u6211\u4eec\u5b9a\u4e49\u4e00\u4e2a\u77e9 \u9635  \\(\\mathbf{X} \\in \\mathbb{R}^{n_{a} \\times n_{b}}\\), \u5176\u4e2d  \\(i^{\\text {th }}\\) \u884c\u548c  \\(j^{\\text {th }}\\) \u5217\u4e2d\u7684\u5143\u7d20  \\(x_{i j}\\)\u662f\u9488\u6846   \\(A_{i}\\) \u548c\u771f\u5b9e\u8fb9\u754c\u6846  \\(B_{j}\\) \u7684 \\(\\mathrm{IoU}\\) \u3002\u8be5\u7b97\u6cd5\u5305\u542b\u4ee5\u4e0b\u6b65\u9aa4:<\/p>\n\n\n\n<ol class=\"has-light-pink-background-color has-background\"><li>\u5728\u77e9\u9635 \\(\\mathbf{X}\\) \u4e2d\u627e\u5230\u6700\u5927\u7684\u5143\u7d20, \u5e76\u5c06\u5b83\u7684\u884c\u7d22\u5f15\u548c\u5217\u7d22\u5f15\u5206\u522b\u8868\u793a\u4e3a \\(i_{1}\\) \u548c \\(j_{1}\\) \u3002\u7136\u540e\u5c06\u771f\u5b9e\u8fb9\u754c\u6846 \\(B_{j_{1}}\\) \u5206 \u914d\u7ed9\u9488\u6846 \\(A_{i_{1}}\\) \u3002\u8fd9\u5f88\u76f4\u89c2\uff0c\u56e0\u4e3a \\(A_{i_{1}}\\) \u548c \\(B_{j_{1}}\\) \u662f\u6240\u6709\u9488\u6846\u548c\u771f\u5b9e\u8fb9\u754c\u6846\u914d\u5bf9\u4e2d\u6700\u76f8\u8fd1\u7684\u3002\u5728\u7b2c\u4e00\u4e2a\u5206\u914d\u5b8c \u6210\u540e\uff0c\u4e22\u5f03\u77e9\u9635\u4e2d \\(i_{1}{ }^{\\text {th }}\\) \u884c\u548c \\(j_{1}{ }^{\\text {th }}\\) \u5217\u4e2d\u7684\u6240\u6709\u5143\u7d20\u3002<\/li><li>\u5728\u77e9\u9635 \\(\\mathbf{X}\\) \u4e2d\u627e\u5230\u5269\u4f59\u5143\u7d20\u4e2d\u6700\u5927\u7684\u5143\u7d20, \u5e76\u5c06\u5b83\u7684\u884c\u7d22\u5f15\u548c\u5217\u7d22\u5f15\u5206\u522b\u8868\u793a\u4e3a \\(i_{2}\\) \u548c \\(j_{2}\\) \u3002\u6211\u4eec\u5c06\u771f\u5b9e\u8fb9 \u754c\u6846 \\(B_{j_{2}}\\) \u5206\u914d\u7ed9\u9488\u6846 \\(A_{i_{2}}\\), \u5e76\u4e22\u5f03\u77e9\u9635\u4e2d \\(i_{2}{ }^{\\text {th }}\\) \u884c\u548c \\(j_{2}{ }^{\\text {th }}\\) \u5217\u4e2d\u7684\u6240\u6709\u5143\u7d20\u3002<\/li><li>\u6b64\u65f6\uff0c\u77e9\u9635 \\(\\mathbf{X}\\) \u4e2d\u4e24\u884c\u548c\u4e24\u5217\u4e2d\u7684\u5143\u7d20\u5df2\u88ab\u4e22\u5f03\u3002\u6211\u4eec\u7ee7\u7eed, \u76f4\u5230\u4e22\u5f03\u6389\u77e9\u9635 \\(\\mathbf{X}\\) \u4e2d \\(n_{b}\\) \u5217\u4e2d\u7684\u6240\u6709\u5143\u7d20\u3002 \u6b64\u65f6\uff0c\u6211\u4eec\u5df2\u7ecf\u4e3a\u8fd9 \\(n_{b}\\) \u4e2a\u9488\u6846\u5404\u81ea\u5206\u914d\u4e86\u4e00\u4e2a\u771f\u5b9e\u8fb9\u754c\u6846\u3002<\/li><li>\u53ea\u904d\u5386\u5269\u4e0b\u7684 \\(n_{a}-n_{b}\\) \u4e2a\u9488\u6846\u3002\u4f8b\u5982\uff0c\u7ed9\u5b9a\u4efb\u4f55\u9488\u6846 \\(A_{i}\\), \u5728\u77e9\u9635 \\(\\mathbf{X}\\)\u7684\u7b2c \\(i^{\\text {th }}\\) \u884c\u4e2d\u627e\u5230\u4e0e \\(A_{i}\\) \u7684IoU\u6700\u5927\u7684 \u771f\u5b9e\u8fb9\u754c\u6846 \\(B_{j}\\), \u53ea\u6709\u5f53\u6b64 IoU \u5927\u4e8e\u9884\u5b9a\u4e49\u7684\u9608\u503c\u65f6, \u624d\u5c06 \\(B_{j}\\) \u5206\u914d\u7ed9 \\(A_{i \\circ}\\)<\/li><\/ol>\n\n\n\n<p class=\"has-light-gray-background-color has-background\">6\u3001\u6807\u8bb0\u7c7b\u548c\u504f\u79fb<\/p>\n\n\n\n<p class=\"has-light-pink-background-color has-background\">\u73b0\u5728\u6211\u4eec\u53ef\u4ee5\u4e3a\u6bcf\u4e2a\u951a\u6846\u6807\u8bb0\u5206\u7c7b\u548c\u504f\u79fb\u91cf\u4e86\u3002\u5047\u8bbe\u2f00\u4e2a\u951a\u6846 A \u88ab\u5206\u914d\u4e86\u2f00\u4e2a\u771f\u5b9e\u8fb9\u754c\u6846 B\u3002\u2f00\u2f45\u2faf\uff0c\u951a\u6846A \u7684\u7c7b\u5c06\u88ab\u6807\u8bb0\u4e3a\u4e0e B \u76f8\u540c\u3002\u53e6\u2f00\u2f45\u2faf\uff0c\u951a\u6846 A \u7684\u504f\u79fb\u91cf\u5c06\u6839\u636e B \u548c A \u4e2d\u2f3c\u5750\u6807\u7684\u76f8\u5bf9\u4f4d\u7f6e\u3001\u4ee5\u53ca\u8fd9\u4e24\u4e2a\u6846\u7684\u76f8\u5bf9\u2f24\u5c0f\u8fdb\u2f8f\u6807\u8bb0\u3002\u9274\u4e8e\u6570\u636e\u96c6\u5185\u4e0d\u540c\u7684\u6846\u7684\u4f4d\u7f6e\u548c\u2f24\u5c0f\u4e0d\u540c\uff0c\u6211\u4eec\u53ef\u4ee5\u5bf9\u90a3\u4e9b\u76f8\u5bf9\u4f4d\u7f6e\u548c\u2f24\u5c0f\u5e94\u2f64\u53d8\u6362\uff0c\u4f7f\u5176\u83b7\u5f97\u66f4\u5747\u5300\u5206\u5e03\u3001\u6613\u4e8e\u9002\u5e94\u7684\u504f\u79fb\u91cf\u3002\u5728\u8fd9\u2fa5\uff0c\u6211\u4eec\u4ecb\u7ecd\u2f00\u79cd\u5e38\u2ec5\u7684\u53d8\u6362\u3002\u7ed9\u5b9a\u6846 A \u548c B\uff0c\u4e2d\u2f3c\u5750\u6807\u5206\u522b\u4e3a (xa, ya) \u548c (xb, yb)\uff0c\u5bbd\u5ea6\u5206\u522b\u4e3a wa \u548c wb\uff0c\u2fbc\u5ea6\u5206\u522b\u4e3a ha \u548c hb\u3002\u6211\u4eec\u53ef\u4ee5\u5c06 A \u7684\u504f\u79fb\u91cf\u6807\u8bb0\u4e3a<\/p>\n\n\n\n<p class=\"has-light-pink-background-color has-background\">$$<br>\\left(\\frac{\\frac{x_{b}-x_{a}}{w_{a}}-\\mu_{x}}{\\sigma_{x}}, \\frac{\\frac{y_{b}-y_{a}}{h_{a}}-\\mu_{y}}{\\sigma_{y}}, \\frac{\\log \\frac{w_{b}}{w_{a}}-\\mu_{w}}{\\sigma_{w}}, \\frac{\\log \\frac{h_{b}}{h_{a}}-\\mu_{h}}{\\sigma_{h}}\\right)<br>$$<\/p>\n\n\n\n<p class=\"has-light-pink-background-color has-background\">$$<br>\\text { \u5176\u4e2d\u5e38\u91cf\u7684\u9ed8\u8ba4\u503c\u662f } \\mu_{x}=\\mu_{y}=\\mu_{w}=\\mu_{h}=0, \\sigma_{x}=\\sigma_{y}=0.1 \\text { \u548c } \\sigma_{w}=\\sigma_{h}=0.2 \\text { \u3002 }<br>$$<\/p>\n\n\n\n<p class=\"has-light-gray-background-color has-background\">7\u3001\u2f64\u2fae\u6781\u2f24\u503c\u6291\u5236\u9884\u6d4b\u8fb9\u754c\u6846<\/p>\n\n\n\n<p class=\"has-light-pink-background-color has-background\">\u5728\u9884\u6d4b\u671f\u95f4\uff0c\u6211\u4eec\u5148\u4e3a\u56fe\u50cf\u2f63\u6210\u591a\u4e2a\u951a\u6846\uff0c\u518d\u4e3a\u8fd9\u4e9b\u951a\u6846\u2f00\u2f00\u9884\u6d4b\u7c7b\u522b\u548c\u504f\u79fb\u91cf\u3002\u2f00\u4e2a\u201c\u9884\u6d4b\u597d\u7684\u8fb9\u754c\u6846\u201d\u5219\u6839\u636e\u5176\u4e2d\u67d0\u4e2a\u5e26\u6709\u9884\u6d4b\u504f\u79fb\u91cf\u7684\u951a\u6846\u800c\u2f63\u6210\u3002\u5f53\u6709\u8bb8\u591a\u951a\u6846\u65f6\uff0c\u53ef\u80fd\u4f1a\u8f93\u51fa\u8bb8\u591a\u76f8\u4f3c\u7684\u5177\u6709\u660e\u663e\u91cd\u53e0\u7684\u9884\u6d4b\u8fb9\u754c\u6846\uff0c\u90fd\u56f4\u7ed5\u7740\u540c\u2f00\u2f6c\u6807\u3002\u4e3a\u4e86\u7b80\u5316\u8f93\u51fa\uff0c\u6211\u4eec\u53ef\u4ee5\u4f7f\u2f64 \u2fae\u6781\u2f24\u503c\u6291\u5236 (non-maximum suppression\uff0cNMS)\u5408\u5e76\u5c5e\u4e8e\u540c\u2f00\u2f6c\u6807\u7684\u7c7b\u4f3c\u7684\u9884\u6d4b\u8fb9\u754c\u6846\u3002\u4ee5\u4e0b\u662f\u2fae\u6781\u2f24\u503c\u6291\u5236\u7684\u2f2f\u4f5c\u539f\u7406\u3002\u5bf9\u4e8e\u2f00\u4e2a\u9884\u6d4b\u8fb9\u754c\u6846 B\uff0c\u2f6c\u6807\u68c0\u6d4b\u6a21\u578b\u4f1a\u8ba1\u7b97\u6bcf\u4e2a\u7c7b\u7684\u9884\u6d4b\u6982\u7387\u3002\u5047\u8bbe\u6700\u2f24\u7684\u9884\u6d4b\u6982\u7387\u4e3a p \uff0c\u5219\u8be5\u6982\u7387\u6240\u5bf9\u5e94\u7684\u7c7b\u522b B \u5373\u4e3a\u9884\u6d4b\u7684\u7c7b\u522b\u3002\u5177\u4f53\u6765\u8bf4\uff0c\u6211\u4eec\u5c06 p \u79f0\u4e3a\u9884\u6d4b\u8fb9\u754c\u6846 B \u7684\u7f6e\u4fe1\u5ea6\u3002\u5728\u540c\u2f00\u5f20\u56fe\u50cf\u4e2d\uff0c\u6240\u6709\u9884\u6d4b\u7684\u2fae\u80cc\u666f\u8fb9\u754c\u6846\u90fd\u6309\u7f6e\u4fe1\u5ea6\u964d\u5e8f\u6392\u5e8f\uff0c\u4ee5\u2f63\u6210\u5217\u8868 L\u3002\u7136\u540e\u6211\u4eec\u901a\u8fc7\u4ee5\u4e0b\u6b65\u9aa4\u64cd\u4f5c\u6392\u5e8f\u5217\u8868 L\uff1a<\/p>\n\n\n\n<ol class=\"has-light-pink-background-color has-background\"><li>\u4ece L \u4e2d\u9009\u53d6\u7f6e\u4fe1\u5ea6\u6700\u9ad8\u7684\u9884\u6d4b\u8fb9\u754c\u6846 \\(B_{1}\\) \u4f5c\u4e3a\u57fa\u51c6\uff0c\u7136\u540e\u5c06\u6240\u6709\u4e0e \\(B_{1}\\) \u7684IoU \u8d85\u8fc7\u9884\u5b9a\u9608\u503c\\(\\epsilon\\) \u7684\u975e\u57fa\u51c6 \u9884\u6d4b\u8fb9\u754c\u6846\u4ece L \u4e2d\u79fb\u9664\u3002\u8fd9\u65f6\uff0c L \u4fdd\u7559\u4e86\u7f6e\u4fe1\u5ea6\u6700\u9ad8\u7684\u9884\u6d4b\u8fb9\u754c\u6846\uff0c\u53bb\u9664\u4e86\u4e0e\u5176\u592a\u8fc7\u76f8\u4f3c\u7684\u5176\u4ed6\u9884\u6d4b \u8fb9\u754c\u6846\u3002\u7b80\u800c\u8a00\u4e4b\uff0c\u90a3\u4e9b\u5177\u6709 \u975e\u6781\u5927\u503c\u7f6e\u4fe1\u5ea6\u7684\u8fb9\u754c\u6846\u88ab \u6291\u5236\u4e86\u3002<\/li><li>\u4ece L \u4e2d\u9009\u53d6\u7f6e\u4fe1\u5ea6\u7b2c\u4e8c\u9ad8\u7684\u9884\u6d4b\u8fb9\u754c\u6846 \\(B_{2}\\) \u4f5c\u4e3a\u53c8\u4e00\u4e2a\u57fa\u51c6\uff0c\u7136\u540e\u5c06\u6240\u6709\u4e0e \\(B_{2}\\)\u7684IoU\u5927\u4e8e \\(\\epsilon\\)\u7684\u975e\u57fa\u51c6 \u9884\u6d4b\u8fb9\u754c\u6846\u4ece L \u4e2d\u79fb\u9664\u3002<\/li><li>\u91cd\u590d\u4e0a\u8ff0\u8fc7\u7a0b\uff0c\u76f4\u5230 L \u4e2d\u7684\u6240\u6709\u9884\u6d4b\u8fb9\u754c\u6846\u90fd\u66fe\u88ab\u7528\u4f5c\u57fa\u51c6\u3002\u6b64\u65f6\uff0c L\u4e2d\u4efb\u610f\u4e00\u5bf9\u9884\u6d4b\u8fb9\u754c\u6846\u7684IoU\u90fd \u5c0f\u4e8e\u9608\u503c \\(\\epsilon\\); \u56e0\u6b64\uff0c\u6ca1\u6709\u4e00\u5bf9\u8fb9\u754c\u6846\u8fc7\u4e8e\u76f8\u4f3c\u3002<\/li><li>\u8f93\u51fa\u5217\u8868 L\u4e2d\u7684\u6240\u6709\u9884\u6d4b\u8fb9\u754c\u6846\u3002<\/li><\/ol>\n\n\n\n<h2>SSD\u539f\u7406\uff1a<\/h2>\n\n\n\n<p>\u5728\u4e86\u89e3\u4e0a\u8ff0\u6982\u5ff5\u540e\uff0c\u5f00\u59cb\u5b9e\u73b0SSD\uff08Single Shot MultiBox Detector\uff09<\/p>\n\n\n\n<p>SSD\u548cYolo\u4e00\u6837\u90fd\u662f\u91c7\u7528\u4e00\u4e2aCNN\u7f51\u7edc\u6765\u8fdb\u884c\u68c0\u6d4b\uff0c\u4f46\u662f\u5374\u91c7\u7528\u4e86\u591a\u5c3a\u5ea6\u7684\u7279\u5f81\u56fe\uff0c\u5176\u57fa\u672c\u67b6\u6784\u5982\u56fe3\u6240\u793a\u3002\u4e0b\u9762\u5c06SSD\u6838\u5fc3\u8bbe\u8ba1\u7406\u5ff5\u603b\u7ed3\u4e3a\u4ee5\u4e0b\u4e09\u70b9\uff1a<\/p>\n\n\n\n<p><strong>\uff081\uff09\u91c7\u7528\u591a\u5c3a\u5ea6\u7279\u5f81\u56fe\u7528\u4e8e\u68c0\u6d4b<\/strong><\/p>\n\n\n\n<p>\u6240\u8c13\u591a\u5c3a\u5ea6\u91c7\u7528\u5927\u5c0f\u4e0d\u540c\u7684\u7279\u5f81\u56fe\uff0cCNN\u7f51\u7edc\u4e00\u822c\u524d\u9762\u7684\u7279\u5f81\u56fe\u6bd4\u8f83\u5927\uff0c\u540e\u9762\u4f1a\u9010\u6e10\u91c7\u7528stride=2\u7684\u5377\u79ef\u6216\u8005pool\u6765\u964d\u4f4e\u7279\u5f81\u56fe\u5927\u5c0f\uff0c\u8fd9\u6b63\u5982\u56fe3\u6240\u793a\uff0c\u4e00\u4e2a\u6bd4\u8f83\u5927\u7684\u7279\u5f81\u56fe\u548c\u4e00\u4e2a\u6bd4\u8f83\u5c0f\u7684\u7279\u5f81\u56fe\uff0c\u5b83\u4eec\u90fd\u7528\u6765\u505a\u68c0\u6d4b\u3002\u8fd9\u6837\u505a\u7684\u597d\u5904\u662f\u6bd4\u8f83\u5927\u7684\u7279\u5f81\u56fe\u6765\u7528\u6765\u68c0\u6d4b\u76f8\u5bf9\u8f83\u5c0f\u7684\u76ee\u6807\uff0c\u800c\u5c0f\u7684\u7279\u5f81\u56fe\u8d1f\u8d23\u68c0\u6d4b\u5927\u76ee\u6807\u3002<\/p>\n\n\n\n<p><strong>\uff082\uff09\u91c7\u7528\u5377\u79ef\u8fdb\u884c\u68c0\u6d4b<\/strong><\/p>\n\n\n\n<p>\u4e0eYolo\u6700\u540e\u91c7\u7528\u5168\u8fde\u63a5\u5c42\u4e0d\u540c\uff0cSSD\u76f4\u63a5\u91c7\u7528\u5377\u79ef\u5bf9\u4e0d\u540c\u7684\u7279\u5f81\u56fe\u6765\u8fdb\u884c\u63d0\u53d6\u68c0\u6d4b\u7ed3\u679c\u3002\u5bf9\u4e8e\u5f62\u72b6\u4e3a&nbsp;<img src=\"https:\/\/www.zhihu.com\/equation?tex=m%5Ctimes+n+%5Ctimes+p\" alt=\"[\u516c\u5f0f]\">&nbsp;\u7684\u7279\u5f81\u56fe\uff0c\u53ea\u9700\u8981\u91c7\u7528&nbsp;<img src=\"https:\/\/www.zhihu.com\/equation?tex=3%5Ctimes+3+%5Ctimes+p\" alt=\"[\u516c\u5f0f]\">&nbsp;\u8fd9\u6837\u6bd4\u8f83\u5c0f\u7684\u5377\u79ef\u6838\u5f97\u5230\u68c0\u6d4b\u503c\u3002<\/p>\n\n\n\n<p><strong>\uff083\uff09\u8bbe\u7f6e\u5148\u9a8c\u6846<\/strong><\/p>\n\n\n\n<p>\u5728Yolo\u4e2d\uff0c\u6bcf\u4e2a\u5355\u5143\u9884\u6d4b\u591a\u4e2a\u8fb9\u754c\u6846\uff0c\u4f46\u662f\u5176\u90fd\u662f\u76f8\u5bf9\u8fd9\u4e2a\u5355\u5143\u672c\u8eab\uff08\u6b63\u65b9\u5757\uff09\uff0c\u4f46\u662f\u771f\u5b9e\u76ee\u6807\u7684\u5f62\u72b6\u662f\u591a\u53d8\u7684\uff0cYolo\u9700\u8981\u5728\u8bad\u7ec3\u8fc7\u7a0b\u4e2d\u81ea\u9002\u5e94\u76ee\u6807\u7684\u5f62\u72b6\u3002\u800cSSD\u501f\u9274\u4e86Faster R-CNN\u4e2danchor\u7684\u7406\u5ff5\uff0c<strong>\u6bcf\u4e2a\u5355\u5143\u8bbe\u7f6e\u5c3a\u5ea6\u6216\u8005\u957f\u5bbd\u6bd4\u4e0d\u540c\u7684\u5148\u9a8c\u6846<\/strong>\uff0c<strong>\u9884\u6d4b\u7684\u8fb9\u754c\u6846\uff08bounding boxes\uff09\u662f\u4ee5\u8fd9\u4e9b\u5148\u9a8c\u6846\u4e3a\u57fa\u51c6\u7684<\/strong>\uff0c\u5728\u4e00\u5b9a\u7a0b\u5ea6\u4e0a\u51cf\u5c11\u8bad\u7ec3\u96be\u5ea6\u3002\u4e00\u822c\u60c5\u51b5\u4e0b\uff0c\u6bcf\u4e2a\u5355\u5143\u4f1a\u8bbe\u7f6e\u591a\u4e2a\u5148\u9a8c\u6846\uff0c\u5176\u5c3a\u5ea6\u548c\u957f\u5bbd\u6bd4\u5b58\u5728\u5dee\u5f02\uff0c\u5982\u56fe5\u6240\u793a\uff0c\u53ef\u4ee5\u770b\u5230\u6bcf\u4e2a\u5355\u5143\u4f7f\u7528\u4e864\u4e2a\u4e0d\u540c\u7684\u5148\u9a8c\u6846\uff0c\u56fe\u7247\u4e2d\u732b\u548c\u72d7\u5206\u522b\u91c7\u7528\u6700\u9002\u5408\u5b83\u4eec\u5f62\u72b6\u7684\u5148\u9a8c\u6846\u6765\u8fdb\u884c\u8bad\u7ec3\uff0c\u540e\u9762\u4f1a\u8be6\u7ec6\u8bb2\u89e3\u8bad\u7ec3\u8fc7\u7a0b\u4e2d\u7684\u5148\u9a8c\u6846\u5339\u914d\u539f\u5219<\/p>\n\n\n\n<p>\u4e5f\u5c31\u662f\u8bf4\uff0c\u5728\u4e0a\u97624\u4e2d\u6240\u8bf4<strong>\u7684 \u201c\u6807\u6ce8\u8bad\u7ec3\u6570\u636e\u7684\u951a\u6846\u201d <\/strong>\uff0c\u8fd9\u91cc\u7684 <strong>\u951a<\/strong> \u6846\u5728SSD\u4e2d\u5c31\u662f\u5148\u9a8c\u6846\u3002<\/p>\n\n\n\n<figure class=\"wp-block-image size-large is-style-default\"><img src=\"https:\/\/pic1.zhimg.com\/v2-f6563d6d5a6cf6caf037e6d5c60b7910_r.jpg\" alt=\"\"\/><\/figure>\n\n\n\n<h2>\u7f51\u7edc\u7ed3\u6784<\/h2>\n\n\n\n<p>SSD\u91c7\u7528VGG16\u4f5c\u4e3a\u57fa\u7840\u6a21\u578b\uff0c\u7136\u540e\u5728VGG16\u7684\u57fa\u7840\u4e0a\u65b0\u589e\u4e86\u5377\u79ef\u5c42\u6765\u83b7\u5f97\u66f4\u591a\u7684\u7279\u5f81\u56fe\u4ee5\u7528\u4e8e\u68c0\u6d4b\u3002SSD\u7684\u7f51\u7edc\u7ed3\u6784\u5982\u56fe5\u6240\u793a\u3002\u4e0a\u9762\u662fSSD\u6a21\u578b\uff0c\u4e0b\u9762\u662fYolo\u6a21\u578b\uff0c\u53ef\u4ee5\u660e\u663e\u770b\u5230SSD\u5229\u7528\u4e86\u591a\u5c3a\u5ea6\u7684\u7279\u5f81\u56fe\u505a\u68c0\u6d4b\u3002<\/p>\n\n\n\n<figure class=\"wp-block-image size-large is-style-default\"><img src=\"https:\/\/pic1.zhimg.com\/v2-a43295a3e146008b2131b160eec09cd4_r.jpg\" alt=\"\"\/><\/figure>\n\n\n\n<p>\u5f97\u5230\u4e86\u7279\u5f81\u56fe\u4e4b\u540e\uff0c\u9700\u8981\u5bf9\u7279\u5f81\u56fe\u8fdb\u884c\u5377\u79ef\u5f97\u5230\u68c0\u6d4b\u7ed3\u679c<\/p>\n\n\n\n<p>\u4e0b\u56fe\u7ed9\u51fa\u4e86\u4e00\u4e2a&nbsp;5*5\u5927\u5c0f\u7684\u7279\u5f81\u56fe\u7684\u68c0\u6d4b\u8fc7\u7a0b\u3002\u5176\u4e2dPriorbox\u662f\u5f97\u5230\u5148\u9a8c\u6846\uff0c\u524d\u9762\u5df2\u7ecf\u4ecb\u7ecd\u4e86\u751f\u6210\u89c4\u5219\u3002\u68c0\u6d4b\u503c\u5305\u542b\u4e24\u4e2a\u90e8\u5206\uff1a\u7c7b\u522b\u7f6e\u4fe1\u5ea6\u548c\u8fb9\u754c\u6846\u4f4d\u7f6e\uff0c\u5404\u91c7\u7528\u4e00\u6b213*3&nbsp;\u5377\u79ef\u6765\u8fdb\u884c\u5b8c\u6210\u3002<\/p>\n\n\n\n<figure class=\"wp-block-image size-large is-style-default\"><img src=\"https:\/\/pic1.zhimg.com\/v2-2d20292e51ef0ce4008ef8a1cf860030_r.jpg\" alt=\"\"\/><figcaption>\u3001<\/figcaption><\/figure>\n\n\n\n<h2>\u8bad\u7ec3\u8fc7\u7a0b<\/h2>\n\n\n\n<p><strong>\uff081\uff09\u5148\u9a8c\u6846\u5339\u914d<\/strong><br>\u5728\u8bad\u7ec3\u8fc7\u7a0b\u4e2d\uff0c\u9996\u5148\u8981\u786e\u5b9a\u8bad\u7ec3\u56fe\u7247\u4e2d\u7684ground truth\uff08\u771f\u5b9e\u76ee\u6807\uff09\u4e0e\u54ea\u4e2a\u5148\u9a8c\u6846\u6765\u8fdb\u884c\u5339\u914d\uff0c\u4e0e\u4e4b\u5339\u914d\u7684\u5148\u9a8c\u6846\u6240\u5bf9\u5e94\u7684\u8fb9\u754c\u6846\u5c06\u8d1f\u8d23\u9884\u6d4b\u5b83\u3002\u5728Yolo\u4e2d\uff0cground truth\u7684\u4e2d\u5fc3\u843d\u5728\u54ea\u4e2a\u5355\u5143\u683c\uff0c\u8be5\u5355\u5143\u683c\u4e2d\u4e0e\u5176IOU\u6700\u5927\u7684\u8fb9\u754c\u6846\u8d1f\u8d23\u9884\u6d4b\u5b83\u3002\u4f46\u662f\u5728SSD\u4e2d\u5374\u5b8c\u5168\u4e0d\u4e00\u6837\uff0cSSD\u7684\u5148\u9a8c\u6846\u4e0eground truth\u7684\u5339\u914d\u539f\u5219\u4e3b\u8981\u6709\u4e24\u70b9\u3002\u9996\u5148\uff0c\u5bf9\u4e8e\u56fe\u7247\u4e2d\u6bcf\u4e2aground truth\uff0c\u627e\u5230\u4e0e\u5176IOU\u6700\u5927\u7684\u5148\u9a8c\u6846\uff0c\u8be5\u5148\u9a8c\u6846\u4e0e\u5176\u5339\u914d\uff0c\u8fd9\u6837\uff0c\u53ef\u4ee5\u4fdd\u8bc1\u6bcf\u4e2aground truth\u4e00\u5b9a\u4e0e\u67d0\u4e2a\u5148\u9a8c\u6846\u5339\u914d\u3002\u901a\u5e38\u79f0\u4e0eground truth\u5339\u914d\u7684\u5148\u9a8c\u6846\u4e3a\u6b63\u6837\u672c\uff08\u5176\u5b9e\u5e94\u8be5\u662f\u5148\u9a8c\u6846\u5bf9\u5e94\u7684\u9884\u6d4bbox\uff0c\u4e0d\u8fc7\u7531\u4e8e\u662f\u4e00\u4e00\u5bf9\u5e94\u7684\u5c31\u8fd9\u6837\u79f0\u547c\u4e86\uff09\uff0c\u53cd\u4e4b\uff0c\u82e5\u4e00\u4e2a\u5148\u9a8c\u6846\u6ca1\u6709\u4e0e\u4efb\u4f55ground truth\u8fdb\u884c\u5339\u914d\uff0c\u90a3\u4e48\u8be5\u5148\u9a8c\u6846\u53ea\u80fd\u4e0e\u80cc\u666f\u5339\u914d\uff0c\u5c31\u662f\u8d1f\u6837\u672c\u3002\u4e00\u4e2a\u56fe\u7247\u4e2dground truth\u662f\u975e\u5e38\u5c11\u7684\uff0c \u800c\u5148\u9a8c\u6846\u5374\u5f88\u591a\uff0c\u5982\u679c\u4ec5\u6309\u7b2c\u4e00\u4e2a\u539f\u5219\u5339\u914d\uff0c\u5f88\u591a\u5148\u9a8c\u6846\u4f1a\u662f\u8d1f\u6837\u672c\uff0c\u6b63\u8d1f\u6837\u672c\u6781\u5176\u4e0d\u5e73\u8861\uff0c\u6240\u4ee5\u9700\u8981\u7b2c\u4e8c\u4e2a\u539f\u5219\u3002\u7b2c\u4e8c\u4e2a\u539f\u5219\u662f\uff1a\u5bf9\u4e8e\u5269\u4f59\u7684\u672a\u5339\u914d\u5148\u9a8c\u6846\uff0c\u82e5\u67d0\u4e2aground truth\u7684&nbsp;IOU\u5927\u4e8e\u67d0\u4e2a\u9608\u503c\uff08\u4e00\u822c\u662f0.5\uff09\uff0c\u90a3\u4e48\u8be5\u5148\u9a8c\u6846\u4e5f\u4e0e\u8fd9\u4e2aground truth\u8fdb\u884c\u5339\u914d\u3002\u8fd9\u610f\u5473\u7740\u67d0\u4e2aground truth\u53ef\u80fd\u4e0e\u591a\u4e2a\u5148\u9a8c\u6846\u5339\u914d\uff0c\u8fd9\u662f\u53ef\u4ee5\u7684\u3002\u4f46\u662f\u53cd\u8fc7\u6765\u5374\u4e0d\u53ef\u4ee5\uff0c\u56e0\u4e3a\u4e00\u4e2a\u5148\u9a8c\u6846\u53ea\u80fd\u5339\u914d\u4e00\u4e2aground truth\uff0c\u5982\u679c\u591a\u4e2aground truth\u4e0e\u67d0\u4e2a\u5148\u9a8c\u6846&nbsp;IOU\u5927\u4e8e\u9608\u503c\uff0c\u90a3\u4e48\u5148\u9a8c\u6846\u53ea\u4e0eIOU\u6700\u5927\u7684\u90a3\u4e2aground truth\u8fdb\u884c\u5339\u914d\u3002\u7b2c\u4e8c\u4e2a\u539f\u5219\u4e00\u5b9a\u5728\u7b2c\u4e00\u4e2a\u539f\u5219\u4e4b\u540e\u8fdb\u884c\uff0c\u4ed4\u7ec6\u8003\u8651\u4e00\u4e0b\u8fd9\u79cd\u60c5\u51b5\uff0c\u5982\u679c\u67d0\u4e2aground truth\u6240\u5bf9\u5e94\u6700\u5927&nbsp;IOU\u5c0f\u4e8e\u9608\u503c\uff0c\u5e76\u4e14\u6240\u5339\u914d\u7684\u5148\u9a8c\u6846\u5374\u4e0e\u53e6\u5916\u4e00\u4e2aground truth\u7684IOU\u5927\u4e8e\u9608\u503c\uff0c\u90a3\u4e48\u8be5\u5148\u9a8c\u6846\u5e94\u8be5\u5339\u914d\u8c01\uff0c\u7b54\u6848\u5e94\u8be5\u662f\u524d\u8005\uff0c\u9996\u5148\u8981\u786e\u4fdd\u67d0\u4e2aground truth\u4e00\u5b9a\u6709\u4e00\u4e2a\u5148\u9a8c\u6846\u4e0e\u4e4b\u5339\u914d\u3002\u4f46\u662f\uff0c\u8fd9\u79cd\u60c5\u51b5\u6211\u89c9\u5f97\u57fa\u672c\u4e0a\u662f\u4e0d\u5b58\u5728\u7684\u3002\u7531\u4e8e\u5148\u9a8c\u6846\u5f88\u591a\uff0c\u67d0\u4e2aground truth\u7684\u6700\u5927&nbsp;IOU\u80af\u5b9a\u5927\u4e8e\u9608\u503c\uff0c\u6240\u4ee5\u53ef\u80fd\u53ea\u5b9e\u65bd\u7b2c\u4e8c\u4e2a\u539f\u5219\u65e2\u53ef\u4ee5\u4e86\uff0c\u8fd9\u91cc\u7684<a rel=\"noreferrer noopener\" href=\"https:\/\/github.com\/xiaohu2015\/SSD-Tensorflow\/blob\/master\/nets\/ssd_common.py\" target=\"_blank\">TensorFlow\u7248\u672c<\/a>\u5c31\u662f\u53ea\u5b9e\u65bd\u4e86\u7b2c\u4e8c\u4e2a\u539f\u5219\uff0c\u4f46\u662f\u8fd9\u91cc\u7684<a rel=\"noreferrer noopener\" href=\"https:\/\/github.com\/amdegroot\/ssd.pytorch\/blob\/master\/layers\/box_utils.py\" target=\"_blank\">Pytorch<\/a>\u4e24\u4e2a\u539f\u5219\u90fd\u5b9e\u65bd\u4e86<\/p>\n\n\n\n<p><strong>\uff082\uff09\u635f\u5931\u51fd\u6570<\/strong><br>\u8bad\u7ec3\u6837\u672c\u786e\u5b9a\u4e86\uff0c\u7136\u540e\u5c31\u662f\u635f\u5931\u51fd\u6570\u4e86\u3002\u635f\u5931\u51fd\u6570\u5b9a\u4e49\u4e3a\u4f4d\u7f6e\u8bef\u5dee\uff08locatization loss\uff0c loc\uff09\u4e0e\u7f6e\u4fe1\u5ea6\u8bef\u5dee\uff08confidence loss, conf\uff09\u7684\u52a0\u6743\u548c\uff1a<\/p>\n\n\n\n<p>$$<br>L(x, c, l, g)=\\frac{1}{N}\\left(L_{c o n f}(x, c)+\\alpha L_{l o c}(x, l, g)\\right)<br>$$<br>\u5176\u4e2d N\u662f\u5148\u9a8c\u6846\u7684\u6b63\u6837\u672c\u6570\u91cf\u3002\u8fd9\u91cc\\(x_{i j}^{p} \\in{1,0}\\) \u4e3a\u4e00\u4e2a\u6307\u793a\u53c2\u6570\uff0c\u5f53 \\(x_{i j}^{p}=1\\)\u65f6\u8868\u793a\u7b2c i \u4e2a\u5148\u9a8c\u6846\u4e0e\u7b2c j \u4e2aground truth\u5339\u914d\uff0c\u5e76\u4e14ground truth\u7684\u7c7b\u522b\u4e3a p \u3002 c \u4e3a\u7c7b\u522b\u7f6e\u4fe1\u5ea6\u9884 \u6d4b\u503c\u3002 l\u4e3a\u5148\u9a8c\u6846\u7684\u6240\u5bf9\u5e94\u8fb9\u754c\u6846\u7684\u4f4d\u7f6e\u9884\u6d4b\u503c\uff0c\u800c g \u662fground truth\u7684\u4f4d\u7f6e\u53c2\u6570\u3002\u5bf9\u4e8e\u4f4d\u7f6e\u8bef \u5dee\uff0c\u5176\u91c7\u7528Smooth L1 loss\uff0c\u5b9a\u4e49\u5982\u4e0b:<\/p>\n\n\n\n<figure class=\"wp-block-image is-style-default\"><img src=\"https:\/\/pic3.zhimg.com\/v2-a56019049a04217560ac498b626ad916_r.jpg\" alt=\"\"\/><\/figure>\n\n\n\n<figure class=\"wp-block-image is-style-default\"><img src=\"https:\/\/pic4.zhimg.com\/v2-5853bed6e8796de582647f1e557b623b_r.jpg\" alt=\"\"\/><\/figure>\n\n\n\n<p>\u5bf9\u4e8e\u7f6e\u4fe1\u5ea6\u8bef\u5dee\uff0c\u5176\u91c7\u7528softmax loss: <\/p>\n\n\n\n<figure class=\"wp-block-image is-style-default\"><img src=\"https:\/\/pic4.zhimg.com\/v2-d28ded21949483b0fbb64b3612b0d543_r.jpg\" alt=\"\"\/><\/figure>\n\n\n\n<p>\u2f6c\u6807\u68c0\u6d4b\u6709\u4e24\u79cd\u7c7b\u578b\u7684\u635f\u5931\u3002\u7b2c\u2f00\u79cd\u6709\u5173\u951a\u6846\u7c7b\u522b\u7684\u635f\u5931\uff1a\u6211\u4eec\u53ef\u4ee5\u7b80\u5355\u5730\u91cd\u2f64\u4e4b\u524d\u56fe\u50cf\u5206\u7c7b\u95ee\u9898\u2fa5\u2f00\u76f4\u4f7f\u2f64\u7684\u4ea4\u53c9\u71b5\u635f\u5931\u51fd\u6570\u6765\u8ba1\u7b97\uff1b\u7b2c\u2f06\u79cd\u6709\u5173\u6b63\u7c7b\u951a\u6846\u504f\u79fb\u91cf\u7684\u635f\u5931\uff1a\u9884\u6d4b\u504f\u79fb\u91cf\u662f\u2f00\u4e2a\u56de\u5f52\u95ee\u9898\uff0c \u4f7f\u2f64 L1 \u8303\u6570\u635f\u5931\uff0c\u5373\u9884\u6d4b\u503c\u548c\u771f\u5b9e\u503c\u4e4b\u5dee\u7684\u7edd\u5bf9\u503c<\/p>\n\n\n\n<p><strong>3\uff09\u6570\u636e\u6269\u589e<\/strong><\/p>\n\n\n\n<p>\u91c7\u7528\u6570\u636e\u6269\u589e\uff08Data Augmentation\uff09\u53ef\u4ee5\u63d0\u5347SSD\u7684\u6027\u80fd\uff0c\u4e3b\u8981\u91c7\u7528\u7684\u6280\u672f\u6709\u6c34\u5e73\u7ffb\u8f6c\uff08horizontal flip\uff09\uff0c\u968f\u673a\u88c1\u526a\u52a0\u989c\u8272\u626d\u66f2\uff08random crop &amp; color distortion\uff09\uff0c\u968f\u673a\u91c7\u96c6\u5757\u57df\uff08Randomly sample a patch\uff09\uff08\u83b7\u53d6\u5c0f\u76ee\u6807\u8bad\u7ec3\u6837\u672c\uff09<\/p>\n\n\n\n<h2>\u9884\u6d4b\u8fc7\u7a0b<\/h2>\n\n\n\n<p>\u9884\u6d4b\u8fc7\u7a0b\u6bd4\u8f83\u7b80\u5355\uff0c\u5bf9\u4e8e\u6bcf\u4e2a\u9884\u6d4b\u6846\uff0c\u9996\u5148\u6839\u636e\u7c7b\u522b\u7f6e\u4fe1\u5ea6\u786e\u5b9a\u5176\u7c7b\u522b\uff08\u7f6e\u4fe1\u5ea6\u6700\u5927\u8005\uff09\u4e0e\u7f6e\u4fe1\u5ea6\u503c\uff0c\u5e76\u8fc7\u6ee4\u6389\u5c5e\u4e8e\u80cc\u666f\u7684\u9884\u6d4b\u6846\u3002\u7136\u540e\u6839\u636e\u7f6e\u4fe1\u5ea6\u9608\u503c\uff08\u59820.5\uff09\u8fc7\u6ee4\u6389\u9608\u503c\u8f83\u4f4e\u7684\u9884\u6d4b\u6846\u3002\u5bf9\u4e8e\u7559\u4e0b\u7684\u9884\u6d4b\u6846\u8fdb\u884c\u89e3\u7801\uff0c\u6839\u636e\u5148\u9a8c\u6846\u5f97\u5230\u5176\u771f\u5b9e\u7684\u4f4d\u7f6e\u53c2\u6570\uff08\u89e3\u7801\u540e\u4e00\u822c\u8fd8\u9700\u8981\u505aclip\uff0c\u9632\u6b62\u9884\u6d4b\u6846\u4f4d\u7f6e\u8d85\u51fa\u56fe\u7247\uff09\u3002\u89e3\u7801\u4e4b\u540e\uff0c\u4e00\u822c\u9700\u8981\u6839\u636e\u7f6e\u4fe1\u5ea6\u8fdb\u884c\u964d\u5e8f\u6392\u5217\uff0c\u7136\u540e\u4ec5\u4fdd\u7559top-k\uff08\u5982400\uff09\u4e2a\u9884\u6d4b\u6846\u3002\u6700\u540e\u5c31\u662f\u8fdb\u884cNMS\u7b97\u6cd5\uff0c\u8fc7\u6ee4\u6389\u90a3\u4e9b\u91cd\u53e0\u5ea6\u8f83\u5927\u7684\u9884\u6d4b\u6846\u3002\u6700\u540e\u5269\u4f59\u7684\u9884\u6d4b\u6846\u5c31\u662f\u68c0\u6d4b\u7ed3\u679c\u4e86\u3002<\/p>\n\n\n\n<h2>\u6027\u80fd\u8bc4\u4f30<\/h2>\n\n\n\n<p>\u9996\u5148\u6574\u4f53\u770b\u4e00\u4e0bSSD\u5728VOC2007\uff0cVOC2012\u53caCOCO\u6570\u636e\u96c6\u4e0a\u7684\u6027\u80fd\uff0c\u5982\u88681\u6240\u793a\u3002\u76f8\u6bd4\u4e4b\u4e0b\uff0cSSD512\u7684\u6027\u80fd\u4f1a\u66f4\u597d\u4e00\u4e9b\u3002\u52a0*\u7684\u8868\u793a\u4f7f\u7528\u4e86image expansion data augmentation\uff08\u901a\u8fc7zoom out\u6765\u521b\u9020\u5c0f\u7684\u8bad\u7ec3\u6837\u672c\uff09\u6280\u5de7\u6765\u63d0\u5347SSD\u5728\u5c0f\u76ee\u6807\u4e0a\u7684\u68c0\u6d4b\u6548\u679c\uff0c\u6240\u4ee5\u6027\u80fd\u4f1a\u6709\u6240\u63d0\u5347\u3002<\/p>\n\n\n\n<figure class=\"wp-block-image is-style-default\"><img src=\"https:\/\/pic4.zhimg.com\/v2-295e1a51086205b89ef46e6847a29357_r.jpg\" alt=\"\"\/><figcaption>\u88681 SSD\u5728\u4e0d\u540c\u6570\u636e\u96c6\u4e0a\u7684\u6027\u80fd<\/figcaption><\/figure>\n\n\n\n<p>SSD\u4e0e\u5176\u5b83\u68c0\u6d4b\u7b97\u6cd5\u7684\u5bf9\u6bd4\u7ed3\u679c\uff08\u5728VOC2007\u6570\u636e\u96c6\uff09\u5982\u88682\u6240\u793a\uff0c\u57fa\u672c\u53ef\u4ee5\u770b\u5230\uff0cSSD\u4e0eFaster R-CNN\u6709\u540c\u6837\u7684\u51c6\u786e\u5ea6\uff0c\u5e76\u4e14\u4e0eYolo\u5177\u6709\u540c\u6837\u8f83\u5feb\u5730\u68c0\u6d4b\u901f\u5ea6\u3002<\/p>\n\n\n\n<figure class=\"wp-block-image is-style-default\"><img src=\"https:\/\/pic1.zhimg.com\/v2-09cf380f4fc0572c12acfd5f1372d310_r.jpg\" alt=\"\"\/><figcaption>\u88682 SSD\u4e0e\u5176\u5b83\u68c0\u6d4b\u7b97\u6cd5\u7684\u5bf9\u6bd4\u7ed3\u679c\uff08\u5728VOC2007\u6570\u636e\u96c6\uff09<\/figcaption><\/figure>\n\n\n\n<p>\u6587\u7ae0\u8fd8\u5bf9SSD\u7684\u5404\u4e2atrick\u505a\u4e86\u66f4\u4e3a\u7ec6\u81f4\u7684\u5206\u6790\uff0c\u88683\u4e3a\u4e0d\u540c\u7684trick\u7ec4\u5408\u5bf9SSD\u7684\u6027\u80fd\u5f71\u54cd\uff0c\u4ece\u8868\u4e2d\u53ef\u4ee5\u5f97\u51fa\u5982\u4e0b\u7ed3\u8bba\uff1a<\/p>\n\n\n\n<ul><li>\u6570\u636e\u6269\u589e\u6280\u672f\u5f88\u91cd\u8981\uff0c\u5bf9\u4e8emAP\u7684\u63d0\u5347\u5f88\u5927\uff1b<\/li><li>\u4f7f\u7528\u4e0d\u540c\u957f\u5bbd\u6bd4\u7684\u5148\u9a8c\u6846\u53ef\u4ee5\u5f97\u5230\u66f4\u597d\u7684\u7ed3\u679c\uff1b<\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image is-style-default\"><img src=\"https:\/\/pic4.zhimg.com\/v2-1f12aabd1577fb996cc471814f68b673_r.jpg\" alt=\"\"\/><figcaption>\u88683 \u4e0d\u540c\u7684trick\u7ec4\u5408\u5bf9SSD\u7684\u6027\u80fd\u5f71\u54cd<\/figcaption><\/figure>\n\n\n\n<p>\u540c\u6837\u7684\uff0c\u91c7\u7528\u591a\u5c3a\u5ea6\u7684\u7279\u5f81\u56fe\u7528\u4e8e\u68c0\u6d4b\u4e5f\u662f\u81f3\u5173\u91cd\u8981\u7684\uff0c\u8fd9\u53ef\u4ee5\u4ece\u88684\u4e2d\u770b\u51fa\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image is-style-default\"><img src=\"https:\/\/pic1.zhimg.com\/v2-a4134f06b5d924067e3d262bc5d290d0_r.jpg\" alt=\"\"\/><figcaption>\u88684 \u591a\u5c3a\u5ea6\u7279\u5f81\u56fe\u5bf9SSD\u7684\u5f71\u54cd<\/figcaption><\/figure>\n\n\n\n<p><a href=\"https:\/\/zhuanlan.zhihu.com\/p\/33544892\">\u53c2\u8003\uff1a https:\/\/zhuanlan.zhihu.com\/p\/33544892<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>SSD\u5c5e\u4e8e\u4e00\u9636\u6bb5\u3001anchor-based&nbsp;\u76ee\u6807\u68c0\u6d4b \u57fa\u4e8eanchor-based\u7684\u6280\u672f\u5305\u62ec\u4e00\u4e2a\u9636\u6bb5 &hellip; <a href=\"http:\/\/139.9.1.231\/index.php\/2021\/12\/31\/ssd\/\" class=\"more-link\">\u7ee7\u7eed\u9605\u8bfb<span class=\"screen-reader-text\">SSD\u539f\u7406\u4e0e\u5b9e\u73b0<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[12,25],"tags":[],"_links":{"self":[{"href":"http:\/\/139.9.1.231\/index.php\/wp-json\/wp\/v2\/posts\/997"}],"collection":[{"href":"http:\/\/139.9.1.231\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/139.9.1.231\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/139.9.1.231\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/139.9.1.231\/index.php\/wp-json\/wp\/v2\/comments?post=997"}],"version-history":[{"count":46,"href":"http:\/\/139.9.1.231\/index.php\/wp-json\/wp\/v2\/posts\/997\/revisions"}],"predecessor-version":[{"id":6756,"href":"http:\/\/139.9.1.231\/index.php\/wp-json\/wp\/v2\/posts\/997\/revisions\/6756"}],"wp:attachment":[{"href":"http:\/\/139.9.1.231\/index.php\/wp-json\/wp\/v2\/media?parent=997"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/139.9.1.231\/index.php\/wp-json\/wp\/v2\/categories?post=997"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/139.9.1.231\/index.php\/wp-json\/wp\/v2\/tags?post=997"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}