RaspberryPi Image Acquire Encode and transmit as SSTV

imgxmit.py

#!/usr/bin/env python

"""
This script
* acquires Image
* overlays callsign on Image
* converts image to wav
* plays wav
"""


import io
import time
import subprocess
from os import remove

import picamera
from PIL import Image, ImageFont, ImageDraw
from pysstv.color import MartinM1


def quick_timestamp():
    return time.time()


def xmit(image):
    print "Encoding image to wav file: %s" % quick_timestamp()
    sstv = MartinM1(image, 48000, 16)
    print "Writing wav file: %s" % quick_timestamp()
    sstv.write_wav("out.wav")
    print "Playing wav file: %s" % quick_timestamp()
    wav_filename = "out.wav"
    subprocess.check_call(["aplay", wav_filename])
    remove(wav_filename)


def main():
    timestamp = quick_timestamp()
    image_name = "images/image-%s.jpg" % timestamp

    img = take_image(image_name)

    img = overlay_callsign(img.rotate(180), "W7ASU", timestamp)
    img.save(image_name)
    xmit(img)
    print "imgxmit complete %s" % quick_timestamp()
    print "runtime: %2.5s (s)" % str(time.time() - timestamp)


def overlay_callsign(image, callsign, timestamp):
    """Given a PIL Image Object will overlay the club callsign on the image
    and return the modified image object
    """
    print "Overlaying callsign: %s" % quick_timestamp()
    font = ImageFont.truetype(
        "/usr/share/fonts/truetype/roboto/Roboto-Bold.ttf",
        24
    )
    draw = ImageDraw.Draw(image)
    text = "%s : %s" % (callsign, timestamp)
    draw.text((20, 220), text, (255, 255, 255), font=font)
    return image


def take_image(image_name):
    """Takes image and returns PIL Image object"""
    print "Taking image %s" % image_name

    stream = io.BytesIO()
    with picamera.PiCamera() as camera:
        camera.resolution = (320, 256)
        camera.start_preview()

        time.sleep(2)

        camera.shutter_speed = camera.exposure_speed
        camera.exposure_mode = 'off'
        g = camera.awb_gains
        camera.awb_mode = 'off'
        camera.awb_gains = g

        camera.capture(stream, format='jpeg')

    # "Rewind" the stream to the beginning so we can read its content
    stream.seek(0)
    return Image.open(stream)


if __name__ == '__main__':
    main()

out.txt

Taking image images/image-1443996915.62.jpg
Overlaying callsign: 1443996919.12
Encoding image to wav file: 1443996919.25
Writing wav file: 1443996919.25
Playing wav file: 1443996976.77
Playing WAVE 'out.wav' : Signed 16 bit Little Endian, Rate 48000 Hz, Mono
imgxmit complete 1443997092.12
runtime: 176.4 (s)

pysstv.patch

diff --git a/setup.py b/setup.py
index 6e51294..fe4694e 100644
--- a/setup.py
+++ b/setup.py
@@ -11,7 +11,7 @@ setup(
     url='https://github.com/dnet/pySSTV',
     packages=['pysstv', 'pysstv.tests', 'pysstv.examples'],
     keywords='HAM SSTV slow-scan television Scottie Martin Robot',
-    install_requires = ['PIL',],
+    install_requires = ['pillow',],
     license='MIT',
     classifiers=[
         'Development Status :: 4 - Beta',

RASPI_SSTV_README.md

This is what I did to get the attached script, imgxmit.py, to work on raspbian

Make sure raspberry pi camera is enabled:

raspi_config

Installed system level dependencies

sudo apt-get update && sudo apt-get upgrade
sudo apt-get install python-virtualenv virtualenvwrapper
sudo apt-get install libfreetype6-dev
sudo apt-get install python-dev python-setuptools libtiff5-dev libjpeg8-dev zlib1g-dev liblcms2-dev libwebp-dev tcl8.5-dev tk8.5-dev python-tk
sudo apt-get install vim git
git clone https://github.com/dnet/pySSTV.git
mkvirtualenv pysstv
cd pysstv
pip install wheel
pip install -U pip
pip install -r requirements.txt
# edit setup.py as shown in the attached patch (or apply patch)
pip install -e .
mkdir images
./imgxmit.py

requirements.txt

picamera==1.10
Pillow==3.0.0

Here's some tweets with pictures sent by this code

https://twitter.com/godber/status/652524553021714432

https://twitter.com/godber/status/652911195473637376