Tag archives: imagemagick

Streams of data

01Feb10

One of my overall goals is to find a way to databend live video. I’m sure there’s a way to do it with Processing and Pure:Data but I’m not yet proficient in those programs so they’re out of the question for now. In the meantime I thought to try and hack the Echobender script to databend my webcam images.

tonyg provides a great tutorial on how to convert live webcam images into audio, which I’ve used as a starting point for my hack.

The process for making it works is as follows:

  • Images from the webcam are saved to the computer
  • These are converted to a .bmp file then renamed to a .raw file
  • Sox applies an audio effect to the .raw file
  • The .raw file is converted back to a .bmp then to a .jpg
  • The updated webcam image is displayed to a window and updated once every second

Sound overly complicated? It probably is. Like the Echobender script you’ll need ImageMagick and Sox but we’ll also be using Webcam, which you can install via “sudo apt-get install webcam”

If you haven’t already, create a file called “.webcamrc” in your home directory (/home/yourusername) and enter this text into it:

[grab]
delay = 0
text = “”

[ftp]
local = 1
tmp = uploading.jpg
file = webcam.jpg
dir = .
debug = 1

Now create a file called grabframe, place it in your home directory and fill it with this:

#!/bin/sh

while [ ! -e webcam.jpg ]; do sleep 0.1; done
convert webcam.jpg frame.bmp
cp frame.bmp frame.raw
sox -r 482170 -e u-law frame.raw frame2.raw echos 0.8 0.9 5000 0.3 1800 0.25
convert -size 640x240 -depth 4 rgb:frame2.raw -trim -flip -flop output.bmp
convert output-0.bmp output.jpg

To start things running, open up three terminal instances:

  • In shell number one, run “webcam”.
  • In shell number two, run “while true; do ./grabframe ; done”.
  • In shell number three, run “display -update 1 output.jpg”

    • Voila!

    I know it’s quite slow, but I haven’t yet found a way to update faster and it’ll still be restricted by the time it takes Sox/ImageMagick to perform their conversions.

    Thanks again to tonyg, Imbecil and Mez for their help and inspiration

Filed under Tutorials| Tagged , , , , , , , | No Comments

Echobender

01Feb10

Myself and Mez recently finished a script called Echobender that automatically databends images.

Click to download

To use it you’ll need:

  • A computer with Linux installed. I don’t have a Windows or Mac PC so I can’t test it on those
  • Sox. On Ubuntu you can install it via “sudo apt-get install sox”
  • Convert, which is part of ImageMagick. On Ubuntu you can install it via “apt-get install imagemagick”

Once you have those installed just execute ./echobender.sh from the terminal and then drop a .jpg or .bmp file into it. The output will be in a folder called “echo”.

If you look closely at the script you can see a way to convert any data into an image! I’ll leave that one up to you… Here’s the source code for all those interested:

#!/bin/sh -e
# Echobender
# By Antonio Roberts and Martin Meredith
# www.hellocatfood.com | www.sourceguru.net
# GNU/GPL

segons=`(date "+%Y%m%d%H%M%S")`
outfile="${segons}"

if [ ! -d ./echo ]; then
	mkdir ./echo
fi
clear
echo -e "\033[31m---------------------------------------------------- \033[0m"
echo -e "\033[33m Echobender \033[0m"
echo -e "\033[32m---------------------------------------------------- \033[0m"
echo -e "\033[35m---------------------------------------------------- \033[0m"
read -p "DROP A FILE HERE> " foo
echo -e "\033[32mLets bend $foo \033[0m"
echo -e "\033[35m---------------------------------------------------- \033[0m"
foo="$(echo $foo | sed -e "s/'//" | sed -e "s/'//")"
bn=$(basename $foo | sed -e 's/\.[a-zA-Z0-9]*$//')
imsize=$(identify -format "%wx%h" $foo)
cp $foo ./echo
convert ./echo/${bn}.* ./echo/${bn}.bmp
cp ./echo/${bn}.bmp ./echo/${bn}.raw
sox -r 482170 -e u-law ./echo/${bn}.raw ./echo/${bn}2.raw echo 0.8 0.9 5000 0.3 1800 0.25
convert -size $imsize -depth 8 rgb:./echo/${bn}2.raw ./echo/${bn}.$outfile.bmp
rm ./echo/${bn}.raw ./echo/${bn}2.raw ./echo/${bn}.bmp ./echo/${bn}.jpg
echo -e "\033[33mJob done. Check ./echo \033[0m"
echo -e "\033[31m---------------------------------------------------- \033[0m"

Thanks to Imbecil’s MPegFucker script for much of the inspiration.

Filed under Art| Tagged , , , , , , | No Comments