from skimage import data
import pyqtgraph as pg
from pyqtgraph.Qt import QtGui
import numpy as np

# row-major: rows of array are rows of image
# col-major: cols of array are rows of image
rowmajor = False # should still work if this is switched

if rowmajor:
    pg.setConfigOptions(imageAxisOrder='row-major')

app = pg.mkQApp()

win = QtGui.QMainWindow()
win.resize(800, 800)
imv = pg.ImageView()
win.setCentralWidget(imv)
win.show()

# shape: (300, 451, 3), row-major as loaded
img_data = data.chelsea()
if not rowmajor:
    # as if loaded col-major data
    img_data = img_data.swapaxes(0, 1)

imv.setImage(img_data)
imv.roi.setSize((451, 5)) # width, height
imv.ui.roiBtn.click()

app.exec_()