Hi All,
I have made this test program so as to check how LineSegmentRoi works and
it seems that there is a bug.
Since getArrayRegion seems to do some smart processing so as to deal with
non vertical or horizontal lines, I have added a horizontal line and asked
for a profile.
Values should be (254 0 0) for all the pixels but I get some wrong values
like (255, 13, 14), (255, 228, 23) among good values.
Below is my code
import sys
from itertools import cycle
from pyqtgraph.Qt import QtCore, QtGui, QtWidgets
import pyqtgraph as pg
import cv2
import numpy as np
pg.setConfigOptions(imageAxisOrder='row-major')
class MainWindow(QtWidgets.QMainWindow):
sigKeyPress = QtCore.pyqtSignal(object)
def __init__(self, *args, **kwargs):
super(MainWindow, self).__init__(*args, **kwargs)
self.line = None
self.sigKeyPress.connect(self.key_pressed)
self.setWindowTitle('My Image Viewer')
self.graphWidget = pg.GraphicsLayoutWidget()
self.setCentralWidget(self.graphWidget)
self.view_box = self.graphWidget.addViewBox(lockAspect=True)
self.view_box.invertY(True)
self.img_item = pg.ImageItem(border='w')
self.view_box.addItem(self.img_item)
self.img_item.setZValue(10)
# image taken from https://www.hisour.com/rgb-color-model-24867/
self.image = cv2.imread('RGB-color-model.jpg')
print(self.image.shape)
self.image = cv2.cvtColor(self.image, cv2.COLOR_BGR2RGB)
self.img_item.setImage(self.image)
#
def _update(self):
*""" :return: """ *pass
def update_profile_analyzer(self):
*""" Update statistics measures on selected areas. *
*If no selected area, update statistics on the whole image.
Returns: """ *# LINE PLOT
if not self.line:
return
#
plot, l_coords = self.line.getArrayRegion(self.image, self.img_item,
returnMappedCoords=True)
print(l_coords)
print(plot)
plot = plot.astype(self.image.dtype)
print(plot)
#
print(self.image[164, 246:296])
def add_line(self):
*""" Add a line that will give us the pixel values along that
line Returns: """ *if self.line:
# cannot add more than 1 profile line
return
# define a line length long enough but not larger than the
reference image
self.line = pg.LineSegmentROI([(246, 164), (296, 164)], removable=
True)
self.view_box.addItem(self.line)
self.line.sigRegionChangeFinished.connect(self
.update_profile_analyzer)
#
self.update_profile_analyzer()
def keyPressEvent(self, ev):
super().keyPressEvent(ev)
self.sigKeyPress.emit(ev)
def key_pressed(self, l_ev):
if l_ev.key() == QtCore.Qt.Key_Escape:
self.close()
elif l_ev.key() == QtCore.Qt.Key_Right:
self._update()
app = QtWidgets.QApplication(sys.argv)
my_win = MainWindow()
my_win.show()
my_win.add_line()
app.exec_()
I do not see what is wrong in my code so I tend to think that it is a bug.
Do you confirm ?
Jean-Pierre
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