QFileDialog and OpenCV's imread()-Problem
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Hi, guys,
i want to create a code where i can select different images via a GUI. For this I use
QFileFialog.getOpenFileNames(). After that I want to store the path of the image in a variable to display it with imread/imshow. But it only works if I use the path directly. As soon as I copy the path into a variable it does not work anymore. Can someone give me a hint ?def open_dialog_box(self): filename, _ = np.asarray(QFileDialog.getOpenFileNames(self, 'Select Multi File', 'default', 'All Files (*)')) for name in filename: #import pic pic = cv2.imread(name, cv2.IMREAD_ANYDEPTH) #This doesn't works **pic = cv2.imread("C:\\Users\\Image_name", cv2.IMREAD_ANYDEPTH)** #This works cv2.imshow("Window", pic) app = QApplication(sys.argv) w = Fenster() w.show() sys.exit(app.exec_())The bold line works. But I don't want to enter the whole path every time. I want the path to be automatically stored in a variable and then used to display the image. Is there a method to use a variable instead of typing the whole path ?
@elias_hh said in QFileDialog and OpenCV's imread()-Problem:
Please print out the
nameyou are passing tocv2.imread(name, which you ultimately get vianp.asarray(QFileDialog.getOpenFileNames()), so that you & we can compare it to the whatevercv2.imread("C:\\Users\\Image_name"you say works. Then we will know what the difference is.Which may be as @SGaist says. Or there is some other difference. My question would be take out the
np.asarray(), try withfilename, _ = QFileDialog.getOpenFileNames(self, 'Select Multi File', 'default', 'All Files (*)'). That returns a tuple in Python, and you arenp.asarray()-ing that, so I'm not sure yourfilenameis what you think it is? We'll know once you print outname. -
@Denni-0 said in QFileDialog and OpenCV's imread()-Problem:
I do not have a problem with the forward slashes in a Windows environment
From this Python examples page for cv2.imread(), it seems to be the case since the examples looks like Windows paths (D: drive) with forward slashes
img = cv2.imread('D:/image-1.png') -
I remember reading that recent versions of Windows (well the command line / power shell / maybe another one) improved the support for that. But the OP didn't say which one he is running.
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Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct -
I remember reading that recent versions of Windows (well the command line / power shell / maybe another one) improved the support for that. But the OP didn't say which one he is running.
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@JonB If i do
print(name)then i get the following path like:C:/Users/Image_name. I think the problem is "/". Windows or OpenCV cant handle path with "/". If i use the same code with my macbook, it works fine.@elias_hh
If that's so, it looks like exactly what @SGaist suggested. If you are saying when you use a literal"C:\\Users\\Image_name"(i.e. valueC:\Users\Image_name) it works but when you pass the result fromQFileDialog.getOpenFileNames()which isC:/Users/Image_nameit does not, then you have your difference/answer.cv2.imread(), does not appear to like forward slashes under Windows (forward slashes would be correctly native under Mac/Linux), though that seems to go against the example quoted by @Pablo-J-Rogina ....In any case, try what @SGaist suggested:
nativeName = QDir.toNativeSeparators(name) pic = cv2.imread(nativeName, cv2.IMREAD_ANYDEPTH)Does that indeed now work?
In any case, I would always use https://doc.qt.io/qt-5/qdir.html#toNativeSeparators when passing any Qt-generated path to anything non-Qt, unless the external documentation states it expects paths to be in forward-slash format.
Under Windows each program can deal with paths with
/vs\differently. For example, the following two OS commands differ:dir \w dir /wThe first lists a file named
win the root directory on the current drive (i.e.\w). The second lists files in the current directory, using the/wlisting option. -
Hi, guys,
i apologize for the unnecessary confusion. the problem all along was not the back slash or the fordwar slash, but something completely different. I already mentioned that i get
C:/Users/Image_nameby usingprint(name). But apparently it has nothing to do with it. The bottom line is that the problem is the following:(Pre-information: my code is in the folder "GUI" and in "GUI" is also the folder with the images named "pics")
when i select an image from this path
C:/Users/Myname/Desktop/GUI/pics--> it doesn work, i become forpic = cv2.imread(name, cv2.IMREAD_ANYDEPTH)aprint(pic) = noneAnd here comes the weird part:
when i select the same image from another path like:
C:/Users/Myname/pics--> it works ! But i have realy no idea why. -
Any chances that your Windows is not in English ?
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@elias_hh
Show the actual paths printed out via theprint(name), copied & pasted to here not typed in, of what does work and what does not.@JonB Ok. I show you the
print(name). This is the path, which doesnt work:C:/Users/hrezaie/Desktop/Hamid Rezaie/GUI/pics/mocim_FPLERW_3_3CM_10mm_MPW_6.0_für_Ex_Versuch1.bmpSo, and if i choose the same image but from another path, it works. see here:
C:/Users/hrezaie/Desktop/Hamid Rezaie/pics/mocim_FPLERW_3_3CM_10mm_MPW_6.0_für_Ex_Versuch1.bmpAgain, to repeat. My Python code is in "GUI".
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@JonB Ok. I show you the
print(name). This is the path, which doesnt work:C:/Users/hrezaie/Desktop/Hamid Rezaie/GUI/pics/mocim_FPLERW_3_3CM_10mm_MPW_6.0_für_Ex_Versuch1.bmpSo, and if i choose the same image but from another path, it works. see here:
C:/Users/hrezaie/Desktop/Hamid Rezaie/pics/mocim_FPLERW_3_3CM_10mm_MPW_6.0_für_Ex_Versuch1.bmpAgain, to repeat. My Python code is in "GUI".
@elias_hh
Then show me from a Command Prompt :dir "C:\Users\hrezaie\Desktop\Hamid Rezaie\GUI\pics\mocim_FPLERW_3_3CM_10mm_MPW_6.0_für_Ex_Versuch1.bmp"Please use copy & paste from what I have written. (In Command Prompt, right click should insert what you have copied to the clipboard, or click its menu in top-left-hand corner and Edit > Paste.)
