Python sensor.skip_frames函数代码示例

Important:
    This script should be copied to the OpenMV Cam as `main.py`.

Source:
    https://github.com/openmv/openmv/blob/master/scripts/examples/02-Board-Control/usb_vcp.py

"""
import sensor
import ustruct
import pyb

usb_vcp = pyb.USB_VCP()
# Disable USB interrupt (CTRL-C by default) when sending raw data (i.e. images)
# See: https://docs.openmv.io/library/pyb.USB_VCP.html#pyb.USB_VCP.setinterrupt
usb_vcp.setinterrupt(-1)

sensor.reset()
sensor.set_pixformat(sensor.RGB565)
sensor.set_framesize(sensor.VGA)
sensor.skip_frames(time=2000)  # wait for settings to take effect!

while True:

    command = usb_vcp.recv(4, timeout=5000)

    if command == b'snap':
        image = sensor.snapshot().compress()
        usb_vcp.send(ustruct.pack('<L', image.size()))
        usb_vcp.send(image)

#
# A color code is a blob composed of two or more colors. The example below will
# only track colored objects which have both the colors below in them.

import sensor, image, time, math

# Color Tracking Thresholds (L Min, L Max, A Min, A Max, B Min, B Max)
# The below thresholds track in general red/green things. You may wish to tune them...
thresholds = [(30, 100, 15, 127, 15, 127), # generic_red_thresholds -> index is 0 so code == (1 << 0)
              (30, 100, -64, -8, -32, 32)] # generic_green_thresholds -> index is 1 so code == (1 << 1)
# Codes are or'ed together when "merge=True" for "find_blobs".

sensor.reset()
sensor.set_pixformat(sensor.RGB565)
sensor.set_framesize(sensor.QVGA)
sensor.skip_frames(time = 2000)
sensor.set_auto_gain(False) # must be turned off for color tracking
sensor.set_auto_whitebal(False) # must be turned off for color tracking
clock = time.clock()

# Only blobs that with more pixels than "pixel_threshold" and more area than "area_threshold" are
# returned by "find_blobs" below. Change "pixels_threshold" and "area_threshold" if you change the
# camera resolution. "merge=True" must be set to merge overlapping color blobs for color codes.

while(True):
    clock.tick()
    img = sensor.snapshot()
    for blob in img.find_blobs(thresholds, pixels_threshold=100, area_threshold=100, merge=True):
        if blob.code() == 3: # r/g code == (1 << 1) | (1 << 0)
            # These values depend on the blob not being circular - otherwise they will be shaky.
            if blob.elongation() > 0.5:

# CIFAR-10 Search Just Center Example
#
# CIFAR is a convolutional nueral network designed to classify it's field of view into several
# different object types and works on RGB video data.
#
# In this example we slide the LeNet detector window over the image and get a list of activations
# where there might be an object. Note that use a CNN with a sliding window is extremely compute
# expensive so for an exhaustive search do not expect the CNN to be real-time.

import sensor, image, time, os, nn

sensor.reset()                         # Reset and initialize the sensor.
sensor.set_pixformat(sensor.RGB565)    # Set pixel format to RGB565 (or GRAYSCALE)
sensor.set_framesize(sensor.QVGA)      # Set frame size to QVGA (320x240)
sensor.set_windowing((128, 128))       # Set 128x128 window.
sensor.skip_frames(time=750)           # Don't let autogain run very long.
sensor.set_auto_gain(False)            # Turn off autogain.
sensor.set_auto_exposure(False)        # Turn off whitebalance.

# Load cifar10 network (You can get the network from OpenMV IDE).
net = nn.load('/cifar10.network')
# Faster, smaller and less accurate.
# net = nn.load('/cifar10_fast.network')
labels = ['airplane', 'automobile', 'bird', 'cat', 'deer', 'dog', 'frog', 'horse', 'ship', 'truck']

clock = time.clock()
while(True):
    clock.tick()

    img = sensor.snapshot()

# NOTE!!! You have to use a small power of 2 resolution when using
# find_displacement(). This is because the algorithm is powered by
# something called phase correlation which does the image comparison
# using FFTs. A non-power of 2 resolution requires padding to a power
# of 2 which reduces the usefulness of the algorithm results. Please
# use a resolution like B128X128 or B128X64 (2x faster).

# Your OpenMV Cam supports power of 2 resolutions of 64x32, 64x64,
# 128x64, and 128x128. If you want a resolution of 32x32 you can create
# it by doing "img.pool(2, 2)" on a 64x64 image.

sensor.reset()                         # Reset and initialize the sensor.
sensor.set_pixformat(sensor.GRAYSCALE) # Set pixel format to GRAYSCALE (or RGB565)
sensor.set_framesize(sensor.B128X128)  # Set frame size to 128x128... (or 128x64)...
sensor.skip_frames(time = 2000)        # Wait for settings take effect.
clock = time.clock()                   # Create a clock object to track the FPS.

# Take from the main frame buffer's RAM to allocate a second frame buffer.
# There's a lot more RAM in the frame buffer than in the MicroPython heap.
# However, after doing this you have a lot less RAM for some algorithms...
# So, be aware that it's a lot easier to get out of RAM issues now.
extra_fb = sensor.alloc_extra_fb(sensor.width(), sensor.height(), sensor.GRAYSCALE)
extra_fb.replace(sensor.snapshot())

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

    for y in range(0, sensor.height(), BLOCK_H):
        for x in range(0, sensor.width(), BLOCK_W):

# detection and then thresholding and filtering that image afterwards.

import sensor, image, time

kernel_size = 1 # kernel width = (size*2)+1, kernel height = (size*2)+1
kernel = [-1, -1, -1,\
          -1, +8, -1,\
          -1, -1, -1]
# This is a high pass filter kernel. see here for more kernels:
# http://www.fmwconcepts.com/imagemagick/digital_image_filtering.pdf
thresholds = [(100, 255)] # grayscale thresholds

sensor.reset() # Initialize the camera sensor.
sensor.set_pixformat(sensor.GRAYSCALE) # or sensor.RGB565
sensor.set_framesize(sensor.QQVGA) # or sensor.QVGA (or others)
sensor.skip_frames(time = 2000) # Let new settings take affect.
clock = time.clock() # Tracks FPS.

# On the OV7725 sensor, edge detection can be enhanced
# significantly by setting the sharpness/edge registers.
# Note: This will be implemented as a function later.
if (sensor.get_id() == sensor.OV7725):
    sensor.__write_reg(0xAC, 0xDF)
    sensor.__write_reg(0x8F, 0xFF)

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

    img.morph(kernel_size, kernel)
    img.binary(thresholds)

# Basic Frame Differencing Example
#
# Note: You will need an SD card to run this example.
#
# This example demonstrates using frame differencing with your OpenMV Cam. It's
# called basic frame differencing because there's no background image update.
# So, as time passes the background image may change resulting in issues.

import sensor, image, pyb, os, time

sensor.reset() # Initialize the camera sensor.
sensor.set_pixformat(sensor.RGB565) # or sensor.GRAYSCALE
sensor.set_framesize(sensor.QVGA) # or sensor.QQVGA (or others)
sensor.skip_frames(time = 2000) # Let new settings take affect.
sensor.set_auto_whitebal(False) # Turn off white balance.
clock = time.clock() # Tracks FPS.

if not "temp" in os.listdir(): os.mkdir("temp") # Make a temp directory

print("About to save background image...")
sensor.skip_frames(time = 2000) # Give the user time to get ready.
sensor.snapshot().save("temp/bg.bmp")
print("Saved background image - Now frame differencing!")

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

    # Replace the image with the "abs(NEW-OLD)" frame difference.
    img.difference("temp/bg.bmp")

import sensor, image, time

# For color tracking to work really well you should ideally be in a very, very,
# very, controlled enviroment where the lighting is constant. Additionally, if
# you want to track more than 2 colors you need to set the boundaries for them
# very narrowly. If you try to track... generally red, green, and blue then
# you will end up just tracking everything which you don't want.
red_threshold   = (  40,   60,   60,   90,   50,   70)
blue_threshold  = (   0,   20,  -10,   30,  -60,   10)
# You may need to tweak the above settings for tracking red and blue things...
# Select an area in the Framebuffer to copy the color settings.

sensor.reset() # Initialize the camera sensor.
sensor.set_pixformat(sensor.RGB565) # use RGB565.
sensor.set_framesize(sensor.QQVGA) # use QQVGA for speed.
sensor.skip_frames(10) # Let new settings take affect.
sensor.set_whitebal(False) # turn this off.
clock = time.clock() # Tracks FPS.

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

    blobs = img.find_blobs([red_threshold, blue_threshold])
    merged_blobs = img.find_markers(blobs)
    if merged_blobs:
        for b in merged_blobs:
            # Draw a rect around the blob.
            img.draw_rectangle(b[0:4]) # rect
            img.draw_cross(b[5], b[6]) # cx, cy
            # Draw the color label. b[8] is the color label.

# Untitled - By: kutenai - Wed Aug 10 2016

import sensor

sensor.reset()
sensor.set_pixformat(sensor.RGB565)
sensor.set_framesize(sensor.QVGA)
sensor.skip_frames()

while(True):
    img = sensor.snapshot()

import sensor, image, time

# Setup Camera
sensor.reset()
sensor.set_pixformat(sensor.RGB565)
sensor.set_framesize(sensor.QQVGA)
sensor.skip_frames(10)
threshold = (10, 90, -80, -30, 20, 50)
clock = time.clock()

# Find blobs
while(True):
    clock.tick()
    img = sensor.snapshot()
    for b in img.find_blobs([threshold]):
        img.draw_rectangle(b[0:4])
        print("====\nBlob %s" % str(b))
    print("FPS %d" % clock.fps())

# Sensor Sleep Mode Example.
# This example demonstrates the sensor sleep mode. The sleep mode saves around
# 40mA when enabled and it's automatically cleared when calling sensor reset().

import sensor, image, time

sensor.reset()                      # Reset and initialize the sensor.
sensor.set_pixformat(sensor.RGB565) # Set pixel format to RGB565 (or GRAYSCALE)
sensor.set_framesize(sensor.QVGA)   # Set frame size to QVGA (320x240)
sensor.skip_frames(time = 3000)     # Capture frames for 3000ms.
sensor.sleep(True)                  # Enable sensor sleep mode (saves about 40mA).

# LetNet Example
import sensor, image, time, os, nn

sensor.reset()                         # Reset and initialize the sensor.
sensor.set_contrast(3)
sensor.set_pixformat(sensor.GRAYSCALE) # Set pixel format to RGB565 (or GRAYSCALE)
sensor.set_framesize(sensor.QVGA)      # Set frame size to QVGA (320x240)
sensor.set_windowing((128, 128))       # Set 128x128 window.
sensor.skip_frames(time=100)
sensor.set_auto_gain(False)
sensor.set_auto_exposure(False)

# Load lenet network
net = nn.load('/lenet.network')
labels = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9']

clock = time.clock()                # Create a clock object to track the FPS.
while(True):
    clock.tick()                    # Update the FPS clock.
    img = sensor.snapshot()         # Take a picture and return the image.
    out = net.forward(img.copy().binary([(150, 255)], invert=True))
    max_idx = out.index(max(out))
    score = int(out[max_idx]*100)
    if (score < 70):
        score_str = "??:??%"
    else:
        score_str = "%s:%d%% "%(labels[max_idx], score)
    img.draw_string(0, 0, score_str)

    print(clock.fps())             # Note: OpenMV Cam runs about half as fast when connected
                                   # to the IDE. The FPS should increase once disconnected.

# We're using the robust=True argument for get_regression() in this script which
# computes the linear regression using a much more robust algorithm... but potentially
# much slower. The robust algorithm runs in O(N^2) time on the image. So, YOU NEED
# TO LIMIT THE NUMBER OF PIXELS the robust algorithm works on or it can actually
# take seconds for the algorithm to give you a result... THRESHOLD VERY CAREFULLY!

THRESHOLD = (0, 100) # Grayscale threshold for dark things...
BINARY_VISIBLE = True # Does binary first so you can see what the linear regression
                      # is being run on... might lower FPS though.

import sensor, image, time

sensor.reset()
sensor.set_pixformat(sensor.GRAYSCALE)
sensor.set_framesize(sensor.QQQVGA) # 80x60 (4,800 pixels) - O(N^2) max = 2,3040,000.
sensor.skip_frames(time = 2000)     # WARNING: If you use QQVGA it may take seconds
clock = time.clock()                # to process a frame sometimes.

while(True):
    clock.tick()
    img = sensor.snapshot().binary([THRESHOLD]) if BINARY_VISIBLE else sensor.snapshot()

    # Returns a line object similar to line objects returned by find_lines() and
    # find_line_segments(). You have x1(), y1(), x2(), y2(), length(),
    # theta() (rotation in degrees), rho(), and magnitude().
    #
    # magnitude() represents how well the linear regression worked. It means something
    # different for the robust linear regression. In general, the larger the value the
    # better...
    line = img.get_regression([(255,255) if BINARY_VISIBLE else THRESHOLD], robust = True)

# Note, this script works well assuming most parts of the image do not
# pass the thresholding test... otherwise, you don't get a distance
# benefit.

import sensor, image, time, math, omv

# Set the thresholds to find a white object (i.e. tag border)
thresholds = (150, 255)

sensor.reset()
sensor.set_pixformat(sensor.GRAYSCALE)
if omv.board_type() == "H7": sensor.set_framesize(sensor.VGA)
elif omv.board_type() == "M7": sensor.set_framesize(sensor.QVGA)
else: raise Exception("You need a more powerful OpenMV Cam to run this script")
sensor.skip_frames(time = 200) # increase this to let the auto methods run for longer
sensor.set_auto_gain(False) # must be turned off for color tracking
sensor.set_auto_whitebal(False) # must be turned off for color tracking
clock = time.clock()

# The apriltag code supports up to 6 tag families which can be processed at the same time.
# Returned tag objects will have their tag family and id within the tag family.
tag_families = 0
tag_families |= image.TAG16H5 # comment out to disable this family
tag_families |= image.TAG25H7 # comment out to disable this family
tag_families |= image.TAG25H9 # comment out to disable this family
tag_families |= image.TAG36H10 # comment out to disable this family
tag_families |= image.TAG36H11 # comment out to disable this family (default family)
tag_families |= image.ARTOOLKIT # comment out to disable this family

while(True):