Qt + OpenCV lib for IOS first configuration failed

SGaist · wrote on 9 Jul 2018, 06:19

The filesystem layout follows to some extend the classic Unix style.

From the looks of it, you are rather building OpenCV for the desktop.

Why build from source since they seem to provide pre-built binaries for iOS ?

kybernetes · wrote on 9 Jul 2018, 07:25

i couldnt use it if i know how can i add it i was planning to work with it. as i told, i have a book and i am working on it it explain as like this. i write program same but framework adding is not i made it before.

i didnt understand steps. when i download prebuilt binaries for ios there is no explanation how to set up to my project. i am writing and make it again. please lead me to finish what i did. Now i began

I downloaded opencv ios pact. now it is in my download dir.
i press cmd+shift+h and make a dir which name is opencv

i put ios-pact zip file in this dir and extract it same place

now i open my qt project and connect opencv and qt once for test app. so i need a pri file or sthing. please tell me what i will do next to add opencv to my project.

After all i made it just once and i can use it if i know how i made it.

Best regards

SGaist · wrote on 9 Jul 2018, 21:37

LIBS += -F/path/to/opencv -framework opencv2

-F is the equivalent of -L but for macOS/iOS frameworks.
-framework is the equivalent of -l but for macOS/iOS frameworks.

kybernetes · 7 Sept 2018, 23:33

am i understand right. i just wright "LIBS += -F/path/to/opencv -framework opencv2" to pri file and i will create pri file where and how can i add it to path or something what i dont know now :) i am sorry as you understand i just try to make a program with qt + opencv to my personal i phone. later i will convert it also android but the main idea is iphone now.

i am working on amin ahmadi tazehkandi's book it is not many information about ios part of programming and it is a little bit harder i think this must be the reason. maybe later mr. tazehkandi makes a unity education system for ios, i would like to be the first customer of it :)

https://www.amazon.com/Computer-Vision-OpenCV-multithreaded-cross-platform/dp/178847239X/ref=asap_bc?ie=UTF8

but i dont know to much. i think i need some push than i can go by myself.

what can i add main.cpp to work with opencv framework codes as you see in below
"Mat image = imread("/Users/kontrolog/Desktop/test1.png");"

thanks a lot.
Best regards.

jsulm · wrote on 10 Jul 2018, 04:41

@kybernetes You need to include OpenCV header file(s) you need in your main.cpp

kybernetes · 7 Oct 2018, 06:09

how can i add it to my main.cpp

as you see when i tried to add by include there is no opencv or opencv2, i appears only opencl-c.h and it is not about me.

for example "Mat image = imread("/Users/kontrolog/Desktop/test1.png");" if i play this code, what i can add my main.cpp file and how.

as you see i put opencv2.framework file in opencv dir where is here "/Users/kontrolog/opencv/" and inside of it

and i put my pri file is also opencv dir

and inside of my pri file is i add headers line now and i make qmake again project file but it didnt work

and after it i cleared headers line in pri file and by right click on source add existing file

i add headers opencv.hpp file from that path "/Users/kontrolog/opencv/opencv2.framework/Versions/A/Headers"

but it also doesnt work and i take same error again.

best regards.

jsulm · wrote on 10 Jul 2018, 06:24

@kybernetes You should NOT add header files from OpenCV via "Add Existing Files..."!
You just need to find out where needed header files are. To use Mat you need mat.hpp. It should be somewhere inside Headers directory, simply search for it.

kybernetes · 7 Oct 2018, 06:48

i really thanks to trying help me but i dont know how to add it.

in my book there is a sample code. so i tried to add "opencv2/opencv.hpp" and writer used this hpp files for OSX, he first qmake the opencv source file than add his program. in my problem it is not for MacOSX for IOS and i download ios pack from opencv website so i couldnt add my project the framework or header files as you see. i think opencv.hpp header is enough for Mat function because of the book. But i can find mat.hpp file it doesnt matter. after i find the file what should i do how can i add header file to my project by not being right click add existing file.

should i copy the mat.hpp file inside from framework and paste to my project file?

i really didnt understand how can i add file and this basic program work on ios simulator :)

thanks.

i couldnt find mat.hpp file inside of opencv dir. but i find opencv.hpp and copy paste to my project file than i build it.

ios simulator is worked but it gives an error lite this and i didnt see the picture, program is now worked.

SGaist · wrote on 10 Jul 2018, 06:57

As the error suggest, imshow's backend is not implemented for iOS but that's something you'd have to look with the OpenCV folks.

On a side note, if you want to show something with your Qt application then QCoreApplication is not the right tool as it doesn't start any graphical backend. It's for command line tools.

On a side note, loading a file from your main machine Desktop folder also won't work on your device as the file won't be accessible.

kybernetes · wrote on 10 Jul 2018, 07:02

about error suggest, i just download opencv ios pack from opencv website as i told so i didnt understand that.

side note 1: i will change QCoreApplication, i just copied the sample code from the book.

Side note 2: i thought also as you, i think if i show a picture i should add it to my project file at least. maybe this can be a solution for access the photo

SGaist · wrote on 10 Jul 2018, 07:12

Building OpenCV for iOS by hand or using their pre-built package won't change anything: the highgui doesn't seem to have backend for iOS.

What exact book are you using ?
What are you going to use OpenCV for exactly ?

kybernetes · 7 Oct 2018, 07:22

this is the book which i use

https://www.amazon.com/Computer-Vision-OpenCV-multithreaded-cross-platform/dp/178847239X/ref=asap_bc?ie=UTF8

and i want to use it just because of fast and useful about image proccesing.

İmage processing is not to much i just want to reach my phone's photo lib, choose photo, crop, rotate and contras it. than make its size smaller but not much effect photo than upload my webserver. that is all i want to. I want to use qml for pages.

Maybe opencv is too much for my needs but i just dont want to effect photo too much when i resize its size.

if you advice any other solution i can give up opencv now :) for ios and android at least

SGaist · wrote on 10 Jul 2018, 22:02

Why not use QImage ?

kybernetes · 7 Nov 2018, 07:05

at the and i will. as i say i was trying to study step by step from book, and i like study from book now the problem how can i use QImage how i can reach file system, how i crop as i want and how i resize etc...

where can i learn, i check but not use too much time, there is no qt ios book or there is not a unity education. so how can i learn proffesional and ask only the necessary question.

you are so helpful and thank you for that but as you know it is impossible to ask everthing to you, and i am write a game for ios and android before 2 years ago i am not an expert, i have to take help every step of the program to learn good and make a good program.

Now i will use QImage we can think that, and i need to use qml to make apperiance more usefull for app.

i am asking Qml + QImage + IOS + Android for documantation. I need take photo from iphone photo library, crop it, rotate it, change contras and upload webserver, at this time program has to be flexible for all phones, apperiance has to be same iphone 4 5 6 7 8 10 or android device and it was hard to do 2 years ago when i was trying to write a game.

Thanks. please give me an advice than, and i will ask any other problems here.
Best regards.

jsulm · wrote on 11 Jul 2018, 07:09

@kybernetes Take a look at http://doc.qt.io/qt-5/ios-support.html
To learn how to develop for iOS you can get a book about iOS development, it is outside of Qt.

kybernetes · 11 Jul 2018, 08:41

no i dont want to write code with xcode, i want to use qt so i need document about Qt ios android, if and advice of a book i preciate it.

you are speaking every day with qt developper on mobile systems, i think you can better choose a book, or heared a book name which is so easy and usefull,
if you can give advice i will be so happy.

Thanks for all

jsulm · wrote on 11 Jul 2018, 08:41

@kybernetes I did not say you have to use XCode. What I mean is: to know all that platform specific details (like plist, file access, ...) you could get a book about iOS development.
I don't know any book specifically related to Qt development for iOS.

kybernetes · 7 Nov 2018, 13:01

ok than we couldnt find a way to make it usefull qt + opencv for ios and i will change solved the title because there is no way to make me this :)

Please let me know if there is a good book for qt mobile especially for ios but also android let me know.

Best regards.