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Python OpenCV瞧ad image from byte string

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(@sathish)
Member Moderator
Joined: 2 years ago
Posts: 1391
20/05/2021 12:50 pm

I'm trying to load image from a string like as PHP functionimagecreatefromstring

How can I do that?

I have MySQL blob field image. I'm usingMySQLdband don't want to create a temporary file for working with images in PyOpenCV.

NOTE: need cv (not cv2) wrapper function


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(@ganesh)
Noble Member
Joined: 2 years ago
Posts: 1362
20/05/2021 12:51 pm

You can easily use this 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)

After this, add the conversion fromnumpy.ndarraytocv2.cv.iplimage, so the above script will print:


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