Introduction to OpenCV.ppt

Introduction to OpenCV Wei Wang, IDM-PKU Outline Digital image processing Image Retargeting Introduction to OpenCV Digital Image Digital device is used everywhere Camera DV Scanner cell phone The features of digital image It is seen everywhere Convenient to capture, operate transmission, storage What is a digital image? R G B pixel value: 0~255 gray image: 2D matrix, 1 channels data, I(x, y) color image: 3D matrix, 3 channels data, I(x, y, 3) Digital image format BMP: windows 位图 GIF：CompuServe Gif JPEG：静态图像专家组制定 PNG：便携网络图形 PCX：PCX格式 TGA：Targa TIFF：标记图像格式 PSD：PhotoShop专用格式 DDS：微软DirectX图像格式 EPS … BMP file format BMP File Header Stores general information about the BMP file. Bitmap Information (DIB header) Stores detailed information about the bitmap image. Color Palette Stores the definition of the colors being used for indexed color bitmaps. Bitmap Data Stores the actual image, pixel by pixel. BMP file header typedef struct tagBITMAPFILEHEADER { ?WORDbfType; // 2 bytes, BM DWORD bfSize; // 4 bytes, file size WORDbfReserved1; //  WORDbfReserved2; //  DWORD bfOffBits; // 4 bytes, the offsize} BITMAPFILEHEADER; /sjzlxd/archive/2009/02/22/3923907.aspx Bitmap information typedef struct tagBITMAPINFOHEADER{ DWORD biSize; // 4 bytes, DIB header size LONGbiWidth; // 4 bytes, width LONGbiHeight; // 4 bytes, height WORD biPlanes; // 2 bytes, 1 WORD biBitCount// 2 bytes, color depth: 1,4, 8, 16, 24, 32 DWORD biCompression; // 4 bytes DWORD biSizeImage; // 4 bytes LONGbiXPelsPerMeter; // 4 bytes LONGbiYPelsPerMeter; // 4 bytes DWORD biClrUsed;// 4 bytes DWORD biClrImportant;// 4 bytes } BITMAPINFOHEADER; /sjzlxd/archive/2009/02/22/3923907.aspx Bitmap information typedef struct tagBITMAPINFOHEADER{ DWORD biSize; // 4 bytes, DIB header size LONGbiWidth; // 4 bytes, width LONGbiHeight; // 4 bytes, height WORD biPlanes; // 2 bytes, 1 WORD biBitCount// 2 bytes, color depth: 1,4, 8, 16, 24, 32 DWORD biCompression; // 4 bytes DWORD biSizeImage; //