https://dschloe.github.io/tags/image-preprocessing/ Recent content in Image Preprocessing on Data Science | DSChloe Hugo en-US Wed, 02 Jun 2021 14:10:47 +0900 https://dschloe.github.io/programming/2021/06/ch01_fileio/ Wed, 02 Jun 2021 14:10:47 +0900 https://dschloe.github.io/programming/2021/06/ch01_fileio/ <h2 id="1줄-요약">1줄 요약</h2> <ul> <li>OpenCV를 활용한 다양한 이미지 입출력에 대해 배우도록 한다.</li> </ul> <h2 id="readingwriting-an-image-file">Reading/Writing an image file</h2> <ul> <li>이미지 관련 I/O</li> <li>BMP, PNG, JPEG, and TIFF also supported.</li> </ul> <div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-python" data-lang="python"><span style="display:flex;"><span><span style="color:#f92672">import</span> numpy <span style="color:#66d9ef">as</span> np </span></span><span style="display:flex;"><span>img <span style="color:#f92672">=</span> np<span style="color:#f92672">.</span>zeros((<span style="color:#ae81ff">3</span>, <span style="color:#ae81ff">3</span>), dtype<span style="color:#f92672">=</span>np<span style="color:#f92672">.</span>uint8) </span></span><span style="display:flex;"><span>img </span></span></code></pre></div><pre><code>array([[0, 0, 0], [0, 0, 0], [0, 0, 0]], dtype=uint8) </code></pre> <ul> <li>각 픽셀은 8비트 int로 구성되어 있음.</li> <li>각 픽셀의 범위는 0-255, 0은 검은색, 255는 흰색을 의미함.</li> </ul> <div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-python" data-lang="python"><span style="display:flex;"><span><span style="color:#f92672">import</span> cv2 </span></span><span style="display:flex;"><span>img <span style="color:#f92672">=</span> cv2<span style="color:#f92672">.</span>cvtColor(img, cv2<span style="color:#f92672">.</span>COLOR_GRAY2BGR) </span></span><span style="display:flex;"><span>img </span></span></code></pre></div><pre><code>array([[[0, 0, 0], [0, 0, 0], [0, 0, 0]], [[0, 0, 0], [0, 0, 0], [0, 0, 0]], [[0, 0, 0], [0, 0, 0], [0, 0, 0]]], dtype=uint8) </code></pre> <ul> <li>3차원 배열을 의미. 각 채널은 Blue, Green, Red를 의미한다.</li> </ul> <h2 id="image-load">image Load</h2> <ul> <li>Convert PNG into JPEG</li> <li>사용할 이미지는 아래와 같다.</li> </ul> <p><img src="https://dschloe.github.io/img/programming/2021/06/ch01_fileIO/MyPic.png#center" alt=""></p>