I'm just developing a little script for screen capturing with Python and analyzing the data for Ambilight. It's already working, but I have some performance issues:
- my script takes about 25%-50% CPU resources while watching youtube (current i5-2410M @ fullHD, script should be optimized for i7-6670k @ 4k (my new pc))
- I'm able to capture about 11 fps, which is enough for ambilight, but if I would be able to capture faster, I can put delays between the shots and reduce resources
- Only the main monitor is captured, would be great if I can choose.
My Script:
import time
import asyncio
import websockets
from PIL import ImageGrab
from PIL import ImageStat
from PIL import ImageEnhance
# Analyzing the image and deleting black borders from movies (21:9 or 4:3)
def analyze_borders(debug=False):
min_size = 3
im = ImageGrab.grab()
width, height = im.size
box = []
for x in range(0, height):
# check top
line = im.crop((0, x, width, x + 1))
if debug:
print("TOP", ImageStat.Stat(line).median)
if ImageStat.Stat(line).median > [1, 1, 1]:
box.append(x)
break
if x >= height / min_size:
box.append(int(height / min_size))
break
for x in range(height, 0, -1):
# check bottom
line = im.crop((0, x, width, x + 1))
if debug:
print("BOTTOM", ImageStat.Stat(line).median)
if ImageStat.Stat(line).median > [1, 1, 1]:
box.append(height - x - 1)
break
if x <= height / min_size:
box.append(int(height / min_size))
break
for x in range(0, width):
# check left
line = im.crop((x, 0, x + 1, height))
if debug:
print("LEFT", ImageStat.Stat(line).median)
if ImageStat.Stat(line).median > [1, 1, 1]:
box.append(x)
break
if x >= width / min_size:
box.append(int(width / min_size))
break
for x in range(width, 0, -1):
# check right
line = im.crop((x, 0, x + 1, height))
if debug:
print("RIGHT", ImageStat.Stat(line).median)
if ImageStat.Stat(line).median > [1, 1, 1]:
box.append(width - x - 1)
break
if x <= width / min_size:
box.append(int(width / min_size))
break
return box
def capture():
return ImageGrab.grab()
@asyncio.coroutine
def start():
time1 = time.time()
websocket = yield from websockets.connect('ws://localhost:8887/')
for x in range(0, 1000):
im = capture()
im = ImageEnhance.Color(im).enhance(1)
im = ImageEnhance.Contrast(im).enhance(1)
box = [0, 0, 0, 0]
if x % 100 == 0:
box = analyze_borders()
print(box)
w, h = im.size
im = im.crop((box[2], box[0], w - box[3], h - box[1]))
w, h = im.size
im1 = im.crop((0, 0, int(w / 2), h))
im2 = im.crop((int(w / 2), 0, w, h))
stat1 = ImageStat.Stat(im1)
stat2 = ImageStat.Stat(im2)
# print(str(x) + " Median1: " + str(stat1.median))
# print(str(x) + " Median2: " + str(stat2.median))
yield from websocket.send(str("C1:(" + str(stat1.median[0]) +
", " + str(stat1.median[1]) +
", " + str(stat1.median[2]) + ")"))
yield from websocket.send(str("C2:(" + str(stat2.median[0]) +
", " + str(stat2.median[1]) +
", " + str(stat2.median[2]) + ")"))
yield from websocket.close()
duration = time.time() - time1
print(str(duration))
print(str(1000 / duration))
asyncio.get_event_loop().run_until_complete(start())
The Websocket part is because my LED Stripes are connected to a RaspberryPi which receives the messages. There might be some performance optimization but I think the main problem is in PIL.
I found this answer: https://stackoverflow.com/a/23155761/5481935
I think this is the best method but I don't understand how I can capture the whole screen with win32ui and crop it into parts because I'm just starting with python. At the moment I just crop two parts, but as soon as I have my digital LED Stripe installed behind my screen I am going to capture bit more parts.
Thank you from Germany, Johannes
Edit: I think most optimization is possible at the capture method. Also I think the answer I linked above is very good, but I don't understand how to connect the answer from above with my code: So how can I capture the whole Screen with win32ui and process the result like in my code or convert it to a PIL image?
