python 2.7 - cv2 getTrackbarPos not working -


working opencv3.1 cv2 in python 2.7.12. problem i'm having right that, though following multiple sets of instructions seem use same setup myself or @ least similar one. going these 2 examples: opencv.org , codegenerater's blogspot tutorial. did not forget make callback function or use cv2.gettrackbarpos. feel there must wrong specific order in or image display loop. here have, diaplays image initial trackbar threshold, not update image trackbar callback:

import cv2   #write simple callback function pass trackbar position *arg     def callback(*arg):      pass  #create display window image cv2.namedwindow('frame')   #read in image img = cv2.imread(r'/home/usr/documents/aerial-images/images_with_targets/flight_4/target_10.jpg',0)  #instantiate trackbar goes in our named window , uses callback function cv2.createtrackbar('thresh2','frame',5,15,callback)  #initialize thresholds thresh1=11 thresh2=5  #loop runs until escape key causes break while(true):      #sets threshold 2 trackbar position     thresh2=cv2.gettrackbarpos('thresh2','frame')        #apply laplacian filter ehance edge gradients     th = cv2.laplacian(img,cv2.cv_8uc1)     #binarize image adaptive threshold     th = cv2.adaptivethreshold(th,255,cv2.adaptive_thresh_gaussian_c,cv2.thresh_binary_inv,thresh1,thresh2)       #show filtered image     cv2.imshow('frame',th)     #waits escape key breaks out of loop     if cv2.waitkey(0) & 0xff == ord('q'):         break   #close our display window      cv2.destroyallwindows()

the answer quite simple really. upon viewing older code wrote, realized needed change wait key 0 1:

if cv2.waitkey(0) & 0xff == ord('q'):     break

became

if cv2.waitkey(1) & 0xff == ord('q'):     break

what did not see forgot camel case cv2.destroyallwindows, made me think display loop still running when not.


-

Comments

Post a Comment

Popular posts from this blog

many to many - Django Rest Framework ManyToMany filter multiple values -

i have 2 models, 1 defining users, other defining labels on these users. using django rest framework create api. able query users @ least labels ids 1 , 2. for instance users' labels are: [(1,2), (1,2,3), (2,3), (1,3)] want query return [(1,2), (1,2,3)] . so far, i've managed query users given label (let's id=1) doing: /api/users/?labels=1 , unable query users labels 1 , 2. i've tried /api/users/?labels=1,2 or /api/users/?labels=1&labels=2 return invalid users, i.e. users without labels 1 or 2... any welcome. thanks, dimitry github test repo: https://github.com/thedimlebowski/drf-m2m-filter code: models.py class label(models.model): name = models.charfield(max_length = 60) class user(models.model): labels = models.manytomanyfield(label) filters.py class userfilter(django_filters.filterset): labels = django_filters.filters.baseinfilter( name='labels', lookup_type='in', ) class meta:...
Read more

java - Jasper subreport showing only one entry from the JSON data source when embedded in the Title band -

Image
i having issues populating data in subreport in title band of main report. data populated correctly in subreport in detail band of main report. trying find wrong in json query. appreciated. json sample data source (expenses.json) { "expenses": { "date": "8 sep 2016", "accounts": [ { "title": "xyz corp (111)", "accountname": "xyz corp", "accountnumber": "111", "transactions": [ { "date": "21 jun 2016", "name": "gas", "price": "17.50" }, { "date": "12 may 2016", "name": "shopping", "price": "111.99" }, { "date": "30 apr 2016", "name...
Read more

Java Entity Manager - JSON reader was expecting a value but found 'db' -

i have code working: entitymanager entitymanager = getentitymanager(); entitymanager.gettransaction().begin(); string query = "db.band.find({})"; list<band> list = (list<band>) entitymanager.createnativequery(query, band.class).getresultlist(); entitymanager.close(); return list; it returns list no problem. want sort list date : entitymanager entitymanager = getentitymanager(); entitymanager.gettransaction().begin(); string query = "db.band.find({something__id:objectid(\"" + myid + "\")}).sort({\"somethingelse.date\":-1})"; list<band> list = (list<band>) entitymanager.createnativequery(query, band.class).getresultlist(); entitymanager.close(); return list; my console gives me message: org.bson.json.jsonparseexception: json reader expecting value found 'db' i checked string working in mongo console , did. ideas? edit: tried putting "something__id" between quotes because would...
Read more