Median Adaptive Threshold Filter Example

# This work is licensed under the MIT license.
# Copyright (c) 2013-2023 OpenMV LLC. All rights reserved.
# https://github.com/openmv/openmv/blob/master/LICENSE
#
# Median Adaptive Threshold Filter Example
#
# This example shows off median filtering with adaptive thresholding.
# When median(threshold=True) the median() method adaptive thresholds the image
# by comparing the median of the pixels around a pixel, minus an offset, with that pixel.

import csi
import time

csi0 = csi.CSI()
csi0.reset()  # Initialize the camera sensor.
csi0.pixformat(csi.RGB565)  # or csi.GRAYSCALE
csi0.framesize(csi.QQVGA)  # or csi.QVGA (or others)
csi0.snapshot(time=2000)  # Let new settings take affect.

clock = time.clock()  # Tracks FPS.

while True:
    clock.tick()  # Track elapsed milliseconds between snapshots().
    img = csi0.snapshot()  # Take a picture and return the image.

    # The first argument to the median filter is the kernel size, it can be
    # either 0, 1, or 2 for a 1x1, 3x3, or 5x5 kernel respectively. The second
    # argument "percentile" is the percentile number to choose from the NxN
    # neighborhood. 0.5 is the median, 0.25 is the lower quartile, and 0.75
    # would be the upper quartile.
    img.median(1, percentile=0.5, threshold=True, offset=5, invert=True)

    print(clock.fps())  # Note: Your OpenMV Cam runs about half as fast while
    # connected to your computer. The FPS should increase once disconnected.