Hey guys:
Good news! I just fixed the bug by myself. Attached is my modified
implementation, which works fine with pyqtgraph 0.10.0. I use v1a to
display the original image and v1b to display the mask.
Thanks,
Xingyu
在 2020年4月6日星期一 UTC+8下午10:45:41，Xingyu Liu写道：
>
> Hi guys:
>
> Thank you so much for your helpful discussion! I'm also a new guy to
> pyqtgraph and trying to find a way to get binary ROI, but when I ran the
> attached testROI.py, an error occurs:
> '''
> Traceback (most recent call last):
> File "testROI.py", line 37, in <module>
> mpossx = roi.getArrayRegion(possx,imgview).astype(int)
> File
> "D:\Program\Miniconda3\envs\bs\lib\site-packages\pyqtgraph\graphicsItems\ROI.py",
>
> line 2027, in getArrayRegion
> sliced = ROI.getArrayRegion(self, data, img, axes=axes,
> fromBoundingRect=True, **kwds)
> File
> "D:\Program\Miniconda3\envs\bs\lib\site-packages\pyqtgraph\graphicsItems\ROI.py",
>
> line 1104, in getArrayRegion
> shape, vectors, origin = self.getAffineSliceParams(data, img, axes,
> fromBoundingRect=fromBR)
> File
> "D:\Program\Miniconda3\envs\bs\lib\site-packages\pyqtgraph\graphicsItems\ROI.py",
>
> line 1129, in getAffineSliceParams
> raise Exception("ROI and target item must be members of the same
> scene.")
> Exception: ROI and target item must be members of the same scene.
> '''
> I guess it is because the function 'ROI.getArrayRegion' has been
> changed/updated over the years. But as a newbie, I don't quite understand
> how to fix it ... Could you please give me some suggestions? Thank you very
> much!!
>
> Best,
> Xingyu
>
> 在 2015年5月18日星期一 UTC+8下午11:50:20，Julien Lhermitte写道：
>>
>> Great I'm glad to hear this! Thanks for the information by the way, I
>> didn't know you could do this but it's a great feature to have (add a
>> function to a class after the fact just like you can do with attributes).
>>
>> I'm not sure which way is more pythonic but I would still rather create a
>> new class with this new method that inherits all methods members of the ROI
>> class used in the long run. This might make things easier to keep track of.
>> If you're not familiar, look up inheritance (like here
>> <http://www.jesshamrick.com/2011/05/18/an-introduction-to-classes-and-inheritance-in-python/>),
>>
>> it's pretty simple to implement. But this is a nice quick fix.
>>
>> On Monday, May 18, 2015 at 3:32:31 AM UTC-4, L. Smash wrote:
>>>
>>> Hi,
>>>
>>> thanks for the nice example! I think I've got it now :)
>>>
>>> What I actually was trying to do is to put your code into a
>>> function/method (like getArrayRegion) and dynamically add it to ROI classes
>>> of pyqtgraph (PolyLineROI, Ellipse.ROI etc.). The problem I stumbled across
>>> was an issue with bound\unbound methods (see here
>>> <http://www.ianlewis.org/en/dynamically-adding-method-classes-or-class-instanc>),
>>>
>>> that's why I got confused with the self variable. Thanks again for your
>>> explanation and the example, it helped me very much!
>>>
>>> Best,
>>> Lars
>>>
>>> Am Freitag, 15. Mai 2015 16:45:27 UTC+2 schrieb Julien Lhermitte:
>>>>
>>>> oops the dimensions were wrong (ROI went out of bounds of data array),
>>>> I have reattached the correct example.
>>>>
>>>> Also, the *self* variable in my previous example would be the
>>>> *theObjectCallingIt* in my current example. It can have whatever name
>>>> you want.
>>>>
>>>> (doing this on my spare time here and there :-( but hope it helps)
>>>>
>>>>
>>>> On Friday, May 15, 2015 at 9:40:12 AM UTC-4, Julien Lhermitte wrote:
>>>>>
>>>>> Hi,
>>>>>
>>>>> I am not completely sure I understand your question but I think
>>>>> your concern is the self variable. Yes, this was just a quick snippet I
>>>>> copied and pasted.
>>>>> First, I believe whenever you call a function in an object, the first
>>>>> parameter given is always a reference to the object itself.
>>>>>
>>>>> So if tiger is part of class Cat, and has member function getColor(),
>>>>> this function:
>>>>> tiger.getColor() is actually a shortcut for Cat.getColor(tiger), so
>>>>> when declaring a function in a class, the function should be declared as:
>>>>>
>>>>> def getColor(theObjectCallingIt, otherparameters...):
>>>>>
>>>>> But let's ignore that for now and just create some self contained
>>>>> code. I have attached it in this message. It generates random data but
>>>>> it's
>>>>> always a good idea to use some sort of image with features to test (just
>>>>> uncomment the relevant lines for that and install PIL image lib for
>>>>> example)
>>>>>
>>>>> I hope this helps!
>>>>>
>>>>> julien
>>>>>
>>>>>
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import numpy as np
import pyqtgraph as pg
from pyqtgraph.Qt import QtCore, QtGui
#random data with random shape
data = np.random.random((1000,1000))
#get data from an image instead, uncommment this
#from PIL import Image
#inputImage='duck.jpg'
#pilImage=Image.open(inputImage)
#data = np.asarray(pilImage)
#data = np.sum(data,axis=2)
#mask same shape as data
mask = np.zeros(data.shape)
#prepare points for dummy ROI
points = np.array([[10,10],[400,10],[400,600],[10,600],[10,10]])
#quick setup of image plotting
pg.mkQApp()
w = pg.GraphicsLayoutWidget()
# imgold = pg.image(data)
# img = pg.image(data)
v1a = w.addPlot(row=0,col=0, lockAspect=True)
img1a = pg.ImageItem(data)
v1a.addItem(img1a)
v1a.autoRange()
v1b = w.addPlot(row=1, col=0, lockAspect=True)
img1b = pg.ImageItem()## View ROI
v1b.addItem(img1b)
v1b.autoRange()
w.show()
#make dummy ROI from points
roi = pg.PolyLineROI(points,closed=True)
#add ROI
v1a.addItem(roi)
# img.addItem(roi)
# imgold.addItem(roi)
# imgview = img.getImageItem()
#Now do the selection
cols,rows = data.shape
m = np.mgrid[:cols,:rows]
possx = m[0,:,:]# make the x pos array
possy = m[1,:,:]# make the y pos array
possx.shape = cols,rows
possy.shape = cols,rows
mpossx = roi.getArrayRegion(possx,img1a).astype(int)
mpossx = mpossx[np.nonzero(mpossx)]#get the x pos from ROI
mpossy = roi.getArrayRegion(possy,img1a).astype(int)
mpossy = mpossy[np.nonzero(mpossy)]# get the y pos from ROI
mask[mpossx,mpossy] = data[mpossx,mpossy]
#uncomment these lines to see the result. Comment them to see
#before the result
img1b.setImage(mask)
v1b.autoRange()
print(np.shape(mask))
#for more questions etc, use the help function
#ex, help(img) will tell you all about member functions and vars
# of the class associated to img
if __name__ == '__main__':
import sys
if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):
QtGui.QApplication.instance().exec_()
