Simple Window using Python
This tutorial shows how to open a Graphical User Interface using the Metavision SDK UI Python API.
import os
import numpy as np
import metavision_sdk_ui as mv_ui
import cv2
Load names of Keys and Buttons
key_to_name = {}
for name, key in mv_ui.UIKeyEvent.__members__.items():
key_to_name[key] = name
button_to_name = {}
for name, button in mv_ui.UIMouseButton.__members__.items():
button_to_name[button] = name
Display an image and set event-callbacks
def test_window(img, use_mt):
# Don't modify the original input image
crt_img = img.copy()
height = img.shape[0]
width = img.shape[1]
# Grayscale mode
if len(img.shape) == 2:
render_mode = mv_ui.Window.RenderMode.GRAY
window_title = "Window GRAY"
cursor_color = 255
mouse_text_color = 255
key_text_color = 255
# Color mode
elif img.shape[2] == 3:
render_mode = mv_ui.Window.RenderMode.BGR
window_title = "Window BGR"
cursor_color = (0, 0, 255)
mouse_text_color = (0, 255, 0)
key_text_color = (255, 0, 0)
else:
print("Incompatible input image's number of channels. Must be either 1 or 3.")
return
# Instantiate window
if use_mt:
w = mv_ui.MTWindow(window_title, img.shape[1], img.shape[0], render_mode)
else:
w = mv_ui.Window(window_title, img.shape[1], img.shape[0], render_mode)
with w:
# Variables used for the callbacks
last_x = 0
last_y = 0
last_mouse_str = ""
last_key_str = ""
close_window = False
# Callback that will be called when the mouse's cursor moves on the current window
def cursor_cb(x, y):
nonlocal last_x
nonlocal last_y
last_x, last_y = int(x), int(y)
# Callback that will be called when a mouse's button is pressed
def mouse_cb(button, action, mods):
nonlocal last_mouse_str
if action == mv_ui.UIAction.RELEASE:
if button in button_to_name:
last_mouse_str = button_to_name[button]
# Callback that will be called when a key is pressed
def keyboard_cb(key, scancode, action, mods):
nonlocal last_key_str
nonlocal close_window
if action == mv_ui.UIAction.RELEASE:
if key in key_to_name:
last_key_str = key_to_name[key]
if key == mv_ui.UIKeyEvent.KEY_ESCAPE:
close_window = True
# Sets the callbacks
w.set_cursor_pos_callback(cursor_cb)
w.set_mouse_callback(mouse_cb)
w.set_keyboard_callback(keyboard_cb)
# Display window
while not w.should_close():
# Dispatch system events to the window
mv_ui.EventLoop.poll_and_dispatch()
# Adjust cursor to current window size
crt_width, crt_height = w.get_size()
cursor_x = int((last_x * width) / crt_width)
cursor_y = int((last_y * height) / crt_height)
# Superimpose callbacks results on the image
crt_img = img.copy()
cv2.circle(crt_img, (cursor_x, cursor_y), 15, cursor_color, 2)
cv2.putText(crt_img, last_mouse_str, (20, 40), cv2.FONT_HERSHEY_SIMPLEX, 1, mouse_text_color, 2)
cv2.putText(crt_img, last_key_str, (20, 80), cv2.FONT_HERSHEY_SIMPLEX, 1, key_text_color, 2)
# Show the image
if use_mt:
w.show_async(crt_img)
else:
w.show(crt_img)
if close_window:
w.set_close_flag()
Grayscale image
# Launch the cell and interact with the window using the cursor, keys and mouse buttons
img = cv2.imread("./prophesee.jpg")
img = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
test_window(img, use_mt=True)
BGR image
# Launch the cell and interact with the window using the cursor, keys and mouse buttons
img = cv2.imread("./prophesee.jpg")
test_window(img, use_mt=True)
