{
 "cells": [
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [],
   "source": [
    "# 引入影象處理庫OpenCV\n",
    "import cv2"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [],
   "source": [
    "# 引入numpy庫，並以np當別名\n",
    "import numpy as np"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [],
   "source": [
    "# 讀取圖片\n",
    "img = cv2.imread('data/image/logo.png')"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [],
   "source": [
    "# 第一種方式"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [],
   "source": [
    "# 分割圖片通道\n",
    "B, G, R = cv2.split(img)\n",
    "\n",
    "# 宣告一個值為0的單通道數組\n",
    "# img.shape[:2] = (img.shape[0], img.shape[1])\n",
    "zeros = np.zeros(img.shape[:2], dtype = \"uint8\")\n",
    "\n",
    "# 分別擴展B、G、R成為三通道。另外兩個通道用上面的值為0的數組填充\n",
    "B = cv2.merge([B, zeros, zeros])\n",
    "G = cv2.merge([zeros, G, zeros])\n",
    "R = cv2.merge([zeros, zeros, R])"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [],
   "source": [
    "# 第二種方法"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {},
   "outputs": [],
   "source": [
    "# 複製原圖(三通道)\n",
    "B = img.copy()\n",
    "G = img.copy()\n",
    "R = img.copy()\n",
    "\n",
    "# set green and red channels to 0\n",
    "B[:, :, 1] = 0\n",
    "B[:, :, 2] = 0\n",
    "\n",
    "# set blue and red channels to 0\n",
    "G[:, :, 0] = 0\n",
    "G[:, :, 2] = 0\n",
    "\n",
    "# set blue and green channels to 0\n",
    "R[:, :, 0] = 0\n",
    "R[:, :, 1] = 0"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [],
   "source": [
    "# 持續等待按鍵，並刷新\n",
    "cv2.waitKey(0)\n",
    "\n",
    "# 關閉所有OpenCV視窗\n",
    "cv2.destroyAllWindows()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "metadata": {},
   "outputs": [],
   "source": [
    "# 將圖片儲存至指定位置\n",
    "cv2.imwrite('data/image/B.jpg', B)\n",
    "cv2.imwrite('data/image/G.jpg', G)\n",
    "cv2.imwrite('data/image/R.jpg', R)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "-1"
      ]
     },
     "execution_count": 10,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# 持續等待按鍵，並刷新\n",
    "cv2.waitKey(0)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "metadata": {},
   "outputs": [],
   "source": [
    "# 關閉所有OpenCV視窗\n",
    "cv2.destroyAllWindows()"
   ]
  }
 ],
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   "display_name": "Python 3",
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