Python code for a sliding window on numpy arrays (images)

sliding-window.ipynb

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        "<a href=\"https://colab.research.google.com/gist/Feyn-Man/c3079cc4f0680e0197310c92ddd52aca/sliding-window.ipynb\" target=\"_parent\"><img src=\"https://colab.research.google.com/assets/colab-badge.svg\" alt=\"Open In Colab\"/></a>"
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      "source": [
        "import numpy as np"
      ],
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      "source": [
        "vec = np.array([[1,1,1,1,1],\n",
        "                [1,1,1,1,1],\n",
        "                [1,1,1,1,1],\n",
        "                [1,1,1,1,1]])"
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      "source": [
        "vec.shape"
      ],
      "execution_count": 9,
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              "(4, 5)"
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      "source": [
        "def sliding_window(img):\n",
        "\n",
        "    (rows, columns) = img.shape\n",
        "    \n",
        "    #dimensioni della finestra con cui scorrere sull'immaigine\n",
        "    windowsize_r = 2\n",
        "    windowsize_c = 2\n",
        "\n",
        "    if windowsize_r > rows or windowsize_c > columns:\n",
        "        print('window is too big. Please specify window dimensions smaller than the shape of the image.')\n",
        "        return\n",
        "    \n",
        "    #punti di inizio e fine della finestra per righe e colonne\n",
        "    start_r = 0\n",
        "    start_c = 0\n",
        "    end_r = start_r + windowsize_r\n",
        "    end_c = start_c + windowsize_c\n",
        "\n",
        "\n",
        "    #si scorre da sx vs dx e dall'alto vs il basso\n",
        "    while (True):#questo per scorrere le righe\n",
        "        while (True): #questo per scorrere le colonne\n",
        "\n",
        "            window = img[start_r:end_r, start_c:end_c]\n",
        "            \n",
        "            print(start_r, \":\", end_r, \",\", start_c, \":\", end_c)\n",
        "            \n",
        "            start_c = start_c + (windowsize_c-1) #sovrapponimento di 10 con la finestra precedente\n",
        "            if start_c < 0: #se ci spostiamo indietro di troppo per la sovrapposizione\n",
        "                print('Error while sliding the window on columns, please check parameters.')\n",
        "                return\n",
        "            end_c = start_c + windowsize_c\n",
        "\n",
        "            if (end_c > columns): #se la fine sborda (fine immagine) si mette come massimo l'ultimo valore di col e si calcola lbp per l'ultima finestra su quella riga\n",
        "                \n",
        "                end_c = columns\n",
        "                window = img[start_r:end_r, start_c:end_c]\n",
        "                \n",
        "                print(start_r, \":\", end_r, \",\", start_c, \":\", columns)\n",
        "                \n",
        "                start_c = 0\n",
        "                end_c = start_c + windowsize_c\n",
        "                break\n",
        "\n",
        "        if (end_r == rows):\n",
        "            # se la fine della finestra è uguale all'ultimo indice di riga allora si è finita l'immagine\n",
        "            break\n",
        "        start_r = start_r + (windowsize_r-1)\n",
        "        if start_r < 0: #se ci spostiamo indietro di troppo per la sovrapposizione\n",
        "            print('Error while sliding the window on rows, please check parameters.')\n",
        "            return\n",
        "        end_r = start_r + windowsize_r\n",
        "        if (end_r > rows): #se la finestra sborda in basso allora si mette come fine della riga della finestra il valore massimo di riga\n",
        "            end_r = rows\n",
        "            \n",
        "    #return features_vec"
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      "source": [
        "sliding_window(vec)"
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      "execution_count": 19,
      "outputs": [
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          "output_type": "stream",
          "text": [
            "0 : 2 , 0 : 2\n",
            "0 : 2 , 1 : 3\n",
            "0 : 2 , 2 : 4\n",
            "0 : 2 , 3 : 5\n",
            "0 : 2 , 4 : 5\n",
            "1 : 3 , 0 : 2\n",
            "1 : 3 , 1 : 3\n",
            "1 : 3 , 2 : 4\n",
            "1 : 3 , 3 : 5\n",
            "1 : 3 , 4 : 5\n",
            "2 : 4 , 0 : 2\n",
            "2 : 4 , 1 : 3\n",
            "2 : 4 , 2 : 4\n",
            "2 : 4 , 3 : 5\n",
            "2 : 4 , 4 : 5\n"
          ],
          "name": "stdout"
        }
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