JR_'s profile - activity

Hello,

I've encoded an webcam image using the following Python code:

result,encimg=cv2.imencode('.jpg', img, [1,95])

In order to send the image over the network it has to be converted into a string or byte array (and vice versa on the receiving end). Any idea's on how to do this?

Thanks in advance and with best regards.

Problem solved!! I removed everything related to open cv and reinstalled it..... It seemed to be using opencv from simplecv....

Hello,

When I run the following code on python the main thread the pictures are displayed correctly:

def picture(self):

    self.capture = cv2.VideoCapture(0)
    cv2.namedWindow("camera")

    framecount = 30
    imagecounter = 0
    bytescounter = 0

    starttime = time.time()

    while self.picturerunning:

        result, img = self.capture.read()

        if result == True:
            cv2.imshow("camera", img)
            cv2.imwrite('temp.jpg', img, [1, 95])
            cv2.waitKey(1)

            read_bytes = open('temp.jpg', 'rb').read()

            bytescounter = bytescounter + len(read_bytes)
            imagecounter = imagecounter + 1

        if imagecounter >= framecount:
            elapsedtime = (time.time() - starttime)

            fps = (framecount / elapsedtime)
            transferspeed = (((bytescounter / 1000) / elapsedtime))

            self.logger.debug('average fps: ' + str(round(fps, 2)))
            self.logger.debug(
                'elapsed time: ' + str(round(elapsedtime, 2)))
            self.logger.debug(
                'average transfer speed (KB/s): ' + str(round(transferspeed, 2)))
            self.logger.debug('----------------------------------------')

            bytescounter = 0
            imagecounter = 0

            starttime = time.time()

However, when I run the same code running on a separate thread the Select "Video Source" dialog is displayed. When I select the correct webcam a black screen is displayed.

I use win7 and have tried following webcams but without success.

I've also tried another system (also Win 7) and here it also doesn't work... Ik can try XP and Ubuntu? Can it be an OS dependent problem?

Hi berak,

Then I get :

TypeError: Required argument 'buf' (pos 3) not found

As an additional note: First I had problems with the following piece of code:

encode_param=[int(cv2.IMWRITE_JPEG_QUALITY), 90] AttributeError: 'module' object has no attribute 'IMWRITE_JPEG_QUALITY'

I fixed this using the following code:

result, encimg = cv2.imencode('.jpg', img, [1, 90])

I use puthon 2.7, windows 7 and opencv 2.4.6. and I try to run the following code:

https://github.com/kyatou/python-opencv_tutorial/blob/master/08_image_encode_decode.py

#import opencv library
import cv2
import sys
import numpy

argvs=sys.argv
if (len(argvs) != 2):
 print 'Usage: # python %s imagefilename' % argvs[0]
 quit()

imagefilename = argvs[1]
try:
  img=cv2.imread(imagefilename, 1)
except:
  print 'faild to load %s' % imagefilename
  quit()

#encode to jpeg format
#encode param image quality 0 to 100. default:95
#if you want to shrink data size, choose low image quality.
encode_param=[1, 90]
result,encimg=cv2.imencode('.jpg',img,encode_param)
if False==result:
  print 'could not encode image!'
  quit()

#decode from jpeg format
decimg=cv2.imdecode(encimg,1)

cv2.imshow('Source Image',img)
cv2.imshow('Decoded image',decimg)
cv2.waitKey(0)
cv2.destroyAllWindows()

I keep getting the following error:

result, encimg = cv2.imencode('.jpg', img, [1, 90]) 
TypeError: 'bool' object is not iterable

I have tried a lot of things: reinstall opencv, convert cv2 to cv code and searched different forums but I keep getting this error. Am I missing something? Is there someone who can run this code without getting the error?

BTW: Other opencv code (taking pictures from webcam) runs without problems....

At the moment I save the image to a temp JPG file. Using the imencode function I want to create the jpg file in the memory.

Thanks in advance and with best regards.