pyqtgraph/examples/ImageItem.py
Ogi Moore d396d33799
Remove the use of pyqtgraph.ptime (#1914)
* Remove the use of pyqtgraph.ptime

With us supporting python3.7+, we have no more need for the ptime module
and can instead safely use perf_counter for everything.

* Address small issues PR turned up

* Reword comment in ImageView
2021-07-22 20:57:50 -07:00

63 lines
1.4 KiB
Python

# -*- coding: utf-8 -*-
"""
Demonstrates very basic use of ImageItem to display image data inside a ViewBox.
"""
## Add path to library (just for examples; you do not need this)
import initExample
from pyqtgraph.Qt import QtCore, QtGui
import numpy as np
import pyqtgraph as pg
from time import perf_counter
app = pg.mkQApp("ImageItem Example")
## Create window with GraphicsView widget
win = pg.GraphicsLayoutWidget()
win.show() ## show widget alone in its own window
win.setWindowTitle('pyqtgraph example: ImageItem')
view = win.addViewBox()
## lock the aspect ratio so pixels are always square
view.setAspectLocked(True)
## Create image item
img = pg.ImageItem(border='w')
view.addItem(img)
## Set initial view bounds
view.setRange(QtCore.QRectF(0, 0, 600, 600))
## Create random image
data = np.random.normal(size=(15, 600, 600), loc=1024, scale=64).astype(np.uint16)
i = 0
updateTime = perf_counter()
elapsed = 0
timer = QtCore.QTimer()
timer.setSingleShot(True)
# not using QTimer.singleShot() because of persistence on PyQt. see PR #1605
def updateData():
global img, data, i, updateTime, elapsed
## Display the data
img.setImage(data[i])
i = (i+1) % data.shape[0]
timer.start(1)
now = perf_counter()
elapsed_now = now - updateTime
updateTime = now
elapsed = elapsed * 0.9 + elapsed_now * 0.1
# print(f"{1 / elapsed:.1f} fps")
timer.timeout.connect(updateData)
updateData()
if __name__ == '__main__':
pg.exec()