Muestra las diferencias entre dos versiones de la página.
| Ambos lados, revisión anterior Revisión previa Próxima revisión | Revisión previa | ||
|
wiki2:opencv [2015/10/17 11:13] alfred [Use in C++] |
wiki2:opencv [2020/05/09 09:25] (actual) |
||
|---|---|---|---|
| Línea 50: | Línea 50: | ||
| return 0; | return 0; | ||
| } | } | ||
| + | </code> | ||
| + | ===== Basic with images ===== | ||
| + | ==== Create black image ==== | ||
| + | <code python> | ||
| + | import numpy as np | ||
| + | blank_image = np.zeros((height,width,3), np.uint8) | ||
| + | </code> | ||
| + | ==== Obtain ROI ==== | ||
| + | <code python> | ||
| + | >>> ball = img[280:340, 330:390] | ||
| + | >>> img[273:333, 100:160] = ball | ||
| </code> | </code> | ||
| - | ===== Use in Python ===== | + | ==== Write an image inside another ==== |
| + | <code python> | ||
| + | black_image[:height, :width] = frame[:,:] | ||
| + | </code> | ||
| + | ==== Obtain the average color ==== | ||
| + | <code python> | ||
| + | color = np.mean(m_roi, axis=0) | ||
| + | </code> | ||
| + | |||
| + | ==== Draw figures ==== | ||
| + | <code python> | ||
| + | cv2.rectangle(black_image, (pos_x, pos_y), (pos_x + size_x, pos_y + size_y), (255, 255, 255)) | ||
| + | </code> | ||
| + | ===== Video Capture ===== | ||
| + | You can capture images and obtain the properties: | ||
| + | <code python> | ||
| + | cap = cv2.VideoCapture(0) | ||
| + | width, height = cap.get(cv2.cv.CV_CAP_PROP_FRAME_WIDTH), cap.get(cv2.cv.CV_CAP_PROP_FRAME_HEIGHT) | ||
| + | </code> | ||
| + | VideoCapture properties in C++ are: CV_CAP_PROP_FRAME_WIDTH... | ||
| + | |||
| + | ===== Others ===== | ||
| + | ==== Get a sample of colors ==== | ||
| + | <code python> | ||
| + | idx_x = np.random.randint(colorset.shape[0], size=_size) | ||
| + | idx_y = np.random.randint(colorset.shape[1], size=_size) | ||
| + | sample = colorset[idx_y, idx_x, :] | ||
| + | </code> | ||
| + | |||
| + | ==== Change the shape of a num.array ==== | ||
| + | Use ''reshape''. | ||