我正在尝试像 PHP 函数一样从字符串加载图像 imagecreatefromstring
I'm trying to load image from string like as PHP function imagecreatefromstring
我该怎么做?
我有 MySQL blob 字段图像.我正在使用 MySQLdb 并且不想创建临时文件来处理 PyOpenCV 中的图像.
I have MySQL blob field image. I'm using MySQLdb and don't want create temporary file for working with images in PyOpenCV.
注意:需要 cv(不是 cv2)包装函数
NOTE: need cv (not cv2) wrapper function
推荐答案这是我通常用来将存储在数据库中的图像转换为 Python 中的 OpenCV 图像的方法.
This is what I normally use to convert images stored in database to OpenCV images in Python.
import numpy as np import cv2 from cv2 import cv # Load image as string from file/database fd = open('foo.jpg') img_str = fd.read() fd.close() # CV2 nparr = np.fromstring(img_str, np.uint8) img_np = cv2.imdecode(nparr, cv2.CV_LOAD_IMAGE_COLOR) # cv2.IMREAD_COLOR in OpenCV 3.1 # CV img_ipl = cv.CreateImageHeader((img_np.shape[1], img_np.shape[0]), cv.IPL_DEPTH_8U, 3) cv.SetData(img_ipl, img_np.tostring(), img_np.dtype.itemsize * 3 * img_np.shape[1]) # check types print type(img_str) print type(img_np) print type(img_ipl)我已经添加了从 numpy.ndarray 到 cv2.cv.iplimage 的转换,所以上面的脚本会打印:
I have added the conversion from numpy.ndarray to cv2.cv.iplimage, so the script above will print:
<type 'str'> <type 'numpy.ndarray'> <type 'cv2.cv.iplimage'>从最新的 numpy 1.18.5 + 开始,np.fromstring 会发出警告,因此应在该位置使用 np.frombuffer.
As of latest numpy 1.18.5 +, the np.fromstring raise a warning, hence np.frombuffer shall be used in that place.
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