Raspberry PI - Revision history

Peter at 14:01, 26 May 2020

2020-05-26T14:01:08Z

← Older revision		Revision as of 14:01, 26 May 2020
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	# [[#Replacing Default Java\|Replace the JDK]]		# [[#Replacing Default Java\|Replace the JDK]]
	# [[Applications\|Download and Run Demonstrations]]		# [[Applications\|Download and Run Demonstrations]]

			{{#ev:youtube\|https://youtu.be/UdrCMB3josw\|400\|center}}

Peter at 18:43, 19 May 2020

2020-05-19T18:43:37Z

← Older revision		Revision as of 18:43, 19 May 2020
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	[https://www.raspberrypi.org/ Raspberry PI's] (RPI) are low cost and very popular ARM devices hobby projects. BoofCV is very easy to set up and run on RPI's. Just compare my experience getting OpenCV and BoofCV up and running ([http://peterabeles.com/blog/?p=241 article]). Basically hours in a best case scenario vs minutes for BoofCV. Things change constantly so maybe it has gotten better since then. It also runs quite fast and well. Check out this these [[Performance:OpenCV:BoofCV\|benchmark]] results.		[https://www.raspberrypi.org/ Raspberry PI's] (RPI) are low cost and very popular ARM devices hobby projects. BoofCV is very easy to set up and run on RPI's. Just compare my experience getting OpenCV and BoofCV up and running ([http://peterabeles.com/blog/?p=241 article]) in 2019. Basically hours in a best case scenario vs minutes for BoofCV. Things change constantly so maybe it has gotten better since then. It also runs quite fast and well. Check out this these [[Performance:OpenCV:BoofCV\|benchmark]] results.

	As is often the case with a RPI to get everything working well and working with your hardware (i.e. a camera) there will be some assembly required. Just as an example, let's say you want to use a RPI to scan QR codes using the RPI camera you need to do the following:		As is often the case with a RPI to get everything working well and working with your hardware (i.e. a camera) there will be some assembly required. Just as an example, let's say you want to use a RPI to scan QR codes using the RPI camera you need to do the following:

	~~# [[#Replacing Default Java\|Replace the JDK]]~~
	# [[#How do I use the Raspberry PI Camera?\|Setup the RPI Camera]]		# [[#How do I use the Raspberry PI Camera?\|Setup the RPI Camera]]
	# [[#Simple Example Application\|Build and Run The Example Project]]		# [[#Simple Example Application\|Build and Run The Example Project]]

	Got an RPI running as a desktop machine? You should run the BoofCV demonstration applications! They mostly work. Videos and cameras can be a bit of an issue though. ~~Newer mp4~~ videos will crash ~~but older mjpeg videos are fine~~. RPI camera requires injecting special code that the demo application's don't have. USB cameras also work but USB is slow on a RPI. Here are the steps you need to follow		Got an RPI running as a desktop machine? You should run the BoofCV demonstration applications! They mostly work. Videos and cameras can be a bit of an issue though. Old mjpeg videos will run fast and mp4 video might work or might crash depending on how its encoded. RPI camera requires injecting special code that the demo application's don't have. USB cameras also work but USB is slow on a RPI. Here are the steps you need to follow

	# [[#Replacing Default Java\|Replace the JDK]]		# [[#Replacing Default Java\|Replace the JDK]]
	# Download and Run Demonstrations		# [[Applications\|Download and Run Demonstrations]]


	__FORCETOC__		__FORCETOC__

	~~= Replacing Default Java =~~		= Simple Programming Example =

	~~The default Java installation on Raspberry PI is not optimized for running on ARM and runs much, much slower than it should. You will need to download another version and use that.~~

	~~# [https://www.bell-sw.com/pages/java-11.0.7/ Download JDK built for Raspberry PI]~~
	~~# Decompress <code>tar -xzf jdk.tar.gz</code>~~
	~~# Move to a location you like, e.g. <code>sudo mv jdk-11 /opt</code>~~
	~~# Add it to your path, e.g. <code>PATH=/opt/jdk-11:$PATH</code>~~

	= Simple Example ~~Application~~ =

	Want a minimalist example? Want to scan for QR codes? Got you covered!		Want a minimalist example? Want to scan for QR codes? Got you covered!
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	= Building BoofCV =		= Building BoofCV =

	You can build BoofCV the usual way, just make sure you use Java 11 or newer ~~to do so and install the ARM optimized JDK~~! ~~On a regular desktop it takes~~ about ~~1 minute to build~~, ~~but~~ on a ~~Raspberry PI it can take 10 minutes or so~~.		To use BoofCV on a Raspberry PI you do NOT need to build it. As was done in the example above, if you use Maven, Gradle, or any other modern build system you can automatically download all dependencies.

			You can build BoofCV the usual way, just make sure you use Java 11 or newer installed! This will take about 10 minutes, which is about 10x slower than it is on a regular Desktop computer.

	To build and install into your local Maven repository:		To build and install into your local Maven repository:
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	<syntaxhighlight lang="bash">		<syntaxhighlight lang="bash">
	/gradlew -Dorg.gradle.java.home=/path/to/jdk-11/ demonstrations		./gradlew -Dorg.gradle.java.home=/path/to/jdk-11/ demonstrations
	</syntaxhighlight>		</syntaxhighlight>

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	/dev/video1 is the device associated with the Raspberry PI camera. You can now access it using Webcam Capture if you follow the instructions in the section [[#How do I get webcams to work?\| above]]		/dev/video1 is the device associated with the Raspberry PI camera. You can now access it using Webcam Capture if you follow the instructions in the section [[#How do I get webcams to work?\| above]]

			= Replacing Default Java =

			In Raspbian prior to 2020 the default Java installed was not optimized for ARM processors and ran very slow. To get decent performance you needed to install a third-party build of Java which was done correctly. More recent builds of Raspbian seem to have fixed the issue, but you can follow the instructions below if you want to be safe.

			# [https://www.bell-sw.com/pages/java-11.0.7/ Download JDK built for Raspberry PI]
			# Decompress <code>tar -xzf jdk.tar.gz</code>
			# Move to a location you like, e.g. <code>sudo mv jdk-11 /opt</code>
			# Add it to your path, e.g. <code>PATH=/opt/jdk-11:$PATH</code>

			This issue is also discussion in a comparison of [[Performance:OpenCV:BoofCV\| BoofCV and OpenCV speed]].

Peter at 15:52, 28 April 2020

2020-04-28T15:52:31Z

← Older revision		Revision as of 15:52, 28 April 2020
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	# [[#Simple Example Application\|Build and Run The Example Project]]		# [[#Simple Example Application\|Build and Run The Example Project]]

	Got an RPI running as a desktop machine? You should run the BoofCV demonstration applications! They mostly work. ~~Cameras~~ can be a bit of an issue though. RPI camera requires injecting special code that the demo application's don't have. USB cameras also work but USB is slow on a RPI. Here are the steps you need to follow		Got an RPI running as a desktop machine? You should run the BoofCV demonstration applications! They mostly work. Videos and cameras can be a bit of an issue though. Newer mp4 videos will crash but older mjpeg videos are fine. RPI camera requires injecting special code that the demo application's don't have. USB cameras also work but USB is slow on a RPI. Here are the steps you need to follow

	# [[#Replacing Default Java\|Replace the JDK]]		# [[#Replacing Default Java\|Replace the JDK]]

Peter at 15:49, 28 April 2020

2020-04-28T15:49:46Z

← Older revision		Revision as of 15:49, 28 April 2020
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	= How do I get webcams to work? =		= How do I get webcams to work? =

	Let's start by saying that USB webcams on a Raspberry PI 3B+ and earlier will be sluggish due to the limitations of USB on Raspberry PI. I've not yet tested a 4B yet. The Rapsberry PI camera will be much faster but the image quality is not ~~good~~...		Let's start by saying that USB webcams on a Raspberry PI 3B+ and earlier will be sluggish due to the limitations of USB on Raspberry PI. I've not yet tested a 4B yet. The Rapsberry PI camera will be much faster but the image quality is not the best...

	Out of the box BoofCV uses [http://webcam-capture.sarxos.pl/ Webcam Capture] due to its easy of use and in Webcam Capture's default configuration it doesn't work on Raspberry PI. The good news is that there is a simple fix that needs to be added to your source code to get it to run on Raspberry PI!		Out of the box BoofCV uses [http://webcam-capture.sarxos.pl/ Webcam Capture] due to its easy of use and in Webcam Capture's default configuration it doesn't work on Raspberry PI. The good news is that there is a simple fix that needs to be added to your source code to get it to run on Raspberry PI!
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	* [https://github.com/sarxos/webcam-capture/tree/master/webcam-capture-drivers/driver-raspberrypi More WebcamCapture Raspberry PI Goodness]		* [https://github.com/sarxos/webcam-capture/tree/master/webcam-capture-drivers/driver-raspberrypi More WebcamCapture Raspberry PI Goodness]
	* [[#Simple Example Application\| Example BoofCV Project Using Webcam Capture]]		* [[#Simple Example Application\| Example BoofCV Project Using Webcam Capture]]
			* [https://groups.google.com/forum/#!topic/boofcv/utxMYaia7Ow BoofCV Forum Discussion]

	After experimentation and TRFM it's recommended that you use <code>RaspividDriver</code> as the driver with Webcam Capture. With a Rapsberry PI camera it goes from 3 FPS to 10 FPS if you do. It still seems a bit slow to me. Let us know if you find a faster way to capture images.		After experimentation and TRFM it's recommended that you use <code>RaspividDriver</code> as the driver with Webcam Capture. With a Rapsberry PI camera it goes from 3 FPS to 10 FPS if you do. It still seems a bit slow to me. Let us know if you find a faster way to capture images.

Peter: /* Simple Example Application */

2020-04-27T15:10:55Z

Simple Example Application

← Older revision		Revision as of 15:10, 27 April 2020
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	Instructions are in the README.MD and it starts by saying to follow the instructions here... You do NOT need to build BoofCV to build that application. It will download all dependencies for you automatically.		Instructions are in the README.MD and it starts by saying to follow the instructions here... You do NOT need to build BoofCV to build that application. It will download all dependencies for you automatically.

	Here's the output that I see when I scan for QR Codes. Everything all together runs at 10 FPS and BoofCV takes about 20ms to process the image if it sees a QR and 10ms if it doesn't. This is on a Raspberry PI 3B+ using the Raspberry PI camera.		Here's the output that I see when I scan for QR Codes. Everything all together runs at 10 FPS and BoofCV takes about 20ms to process the image if it sees a QR and 10ms if it doesn't. Interesting to note that in this case frame capture is the performance bottle neck. This is on a Raspberry PI 3B+ using the Raspberry PI camera.

	<pre>		<pre>

Peter: /* How do I get webcams to work? */

2020-04-27T15:09:27Z

How do I get webcams to work?

← Older revision		Revision as of 15:09, 27 April 2020
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	= How do I get webcams to work? =		= How do I get webcams to work? =

			Let's start by saying that USB webcams on a Raspberry PI 3B+ and earlier will be sluggish due to the limitations of USB on Raspberry PI. I've not yet tested a 4B yet. The Rapsberry PI camera will be much faster but the image quality is not good...

	Out of the box BoofCV uses [http://webcam-capture.sarxos.pl/ Webcam Capture] due to its easy of use and in Webcam Capture's default configuration it doesn't work on Raspberry PI. The good news is that there is a simple fix that needs to be added to your source code to get it to run on Raspberry PI!		Out of the box BoofCV uses [http://webcam-capture.sarxos.pl/ Webcam Capture] due to its easy of use and in Webcam Capture's default configuration it doesn't work on Raspberry PI. The good news is that there is a simple fix that needs to be added to your source code to get it to run on Raspberry PI!
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	* [[#Simple Example Application\| Example BoofCV Project Using Webcam Capture]]		* [[#Simple Example Application\| Example BoofCV Project Using Webcam Capture]]

	~~Performance might be an issue~~ with Webcam Capture. ~~There for~~ you ~~might want~~ to ~~consider some alternatives which may or may not be as user friendly~~.		After experimentation and TRFM it's recommended that you use <code>RaspividDriver</code> as the driver with Webcam Capture. With a Rapsberry PI camera it goes from 3 FPS to 10 FPS if you do. It still seems a bit slow to me. Let us know if you find a faster way to capture images.

	* [https://github.com/Hopding/JRPiCam JRPiCam] uses raspistill to capture images		* [https://github.com/Hopding/JRPiCam JRPiCam] uses raspistill to capture images. Not tried it but probably slower.
	* [https://github.com/lessthanoptimal/libwebcam My fork of libwebcam.] Added a Java wrapper and added more controls. Not supported.		* [https://github.com/lessthanoptimal/libwebcam My fork of libwebcam.] Added a Java wrapper and added more controls. Should be more memory efficient. Not supported.

	If there's another library you find that can capture images and is fast you should be able to wrap it and get the images into BoofCV.		If there's another library you find that can capture images and is fast you should be able to wrap it and get the images into BoofCV.

Peter: /* Simple Example Application */

2020-04-27T15:03:07Z

Simple Example Application

← Older revision		Revision as of 15:03, 27 April 2020
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	Instructions are in the README.MD and it starts by saying to follow the instructions here... You do NOT need to build BoofCV to build that application. It will download all dependencies for you automatically.		Instructions are in the README.MD and it starts by saying to follow the instructions here... You do NOT need to build BoofCV to build that application. It will download all dependencies for you automatically.

	Here's the output that I see when I scan for QR Codes. Everything all together runs at 10 FPS and BoofCV takes about 20ms to process the image if it sees a QR and 10ms if it doesn't.		Here's the output that I see when I scan for QR Codes. Everything all together runs at 10 FPS and BoofCV takes about 20ms to process the image if it sees a QR and 10ms if it doesn't. This is on a Raspberry PI 3B+ using the Raspberry PI camera.

	<pre>		<pre>

Peter: /* Simple Example Application */

2020-04-27T15:02:08Z

Simple Example Application

← Older revision		Revision as of 15:02, 27 April 2020
Line 31:		Line 31:

	Instructions are in the README.MD and it starts by saying to follow the instructions here... You do NOT need to build BoofCV to build that application. It will download all dependencies for you automatically.		Instructions are in the README.MD and it starts by saying to follow the instructions here... You do NOT need to build BoofCV to build that application. It will download all dependencies for you automatically.

			Here's the output that I see when I scan for QR Codes. Everything all together runs at 10 FPS and BoofCV takes about 20ms to process the image if it sees a QR and 10ms if it doesn't.

			<pre>
			0205 processed 640 x 480 in 20.11 (ms) FPS 10.2
			Found 1
			QR "LANDMARK16 1"
			0289 processed 640 x 480 in 14.91 (ms) FPS 10.3
			Nothing detected
			</pre>

	= Building BoofCV =		= Building BoofCV =

Peter at 14:33, 27 April 2020

2020-04-27T14:33:29Z

← Older revision		Revision as of 14:33, 27 April 2020
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	= How do I get webcams to work? =		= How do I get webcams to work? =

	BoofCV uses [http://webcam-capture.sarxos.pl/ Webcam Capture] and in it's default configuration it doesn't work on Raspberry PI. The good news is that there is a simple fix that needs to be added to your source code to get it to run on Raspberry PI! ~~https://github.com/sarxos/webcam-capture/wiki/How-To-Configure-Raspberry-Pi~~		Out of the box BoofCV uses [http://webcam-capture.sarxos.pl/ Webcam Capture] due to its easy of use and in Webcam Capture's default configuration it doesn't work on Raspberry PI. The good news is that there is a simple fix that needs to be added to your source code to get it to run on Raspberry PI!

	~~It should also be pointed out that you don't have to use any of built in tools~~. ~~You just need a way to convert the image into format that~~ BoofCV ~~understands. Once you got the bytes for an image that is often "simple" if you understand image formats.~~		* [https://github.com/sarxos/webcam-capture/wiki/How-To-Configure-Raspberry-Pi Configuring Webcam Capture]
			* [https://github.com/sarxos/webcam-capture/tree/master/webcam-capture-drivers/driver-raspberrypi More WebcamCapture Raspberry PI Goodness]
			* [[#Simple Example Application\| Example BoofCV Project Using Webcam Capture]]

	~~The [[#Simple Example Application\|Simple Example]] has working code that contains the modification~~ you ~~need~~ to do.		Performance might be an issue with Webcam Capture. There for you might want to consider some alternatives which may or may not be as user friendly.

			* [https://github.com/Hopding/JRPiCam JRPiCam] uses raspistill to capture images
			* [https://github.com/lessthanoptimal/libwebcam My fork of libwebcam.] Added a Java wrapper and added more controls. Not supported.

			If there's another library you find that can capture images and is fast you should be able to wrap it and get the images into BoofCV.

	= How do I use the Raspberry PI Camera? =		= How do I use the Raspberry PI Camera? =

	The easiest way to access the camera is to treat it as a UVC device. ~~This way WebcamCapture will recognize it and all the example code will work~~. Unfortunately, you have to tell your Raspberry PI to load the UVC driver each time you boot by doing the following ([https://raspberrypi.stackexchange.com/questions/10480/raspi-camera-board-and-motion Stack Exchange]):		The easiest way to access the camera is to treat it as a UVC device and use a library based on [https://en.wikipedia.org/wiki/Video4Linux V4L]. Unfortunately, you have to tell your Raspberry PI to load the UVC driver each time you boot by doing the following ([https://raspberrypi.stackexchange.com/questions/10480/raspi-camera-board-and-motion Stack Exchange]):

	<syntaxhighlight lang="bash">		<syntaxhighlight lang="bash">

Peter at 01:51, 27 April 2020

2020-04-27T01:51:48Z

← Older revision		Revision as of 01:51, 27 April 2020
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	# [https://www.bell-sw.com/pages/java-11.0.7/ Download JDK built for Raspberry PI]		# [https://www.bell-sw.com/pages/java-11.0.7/ Download JDK built for Raspberry PI]
	# Decompress `tar -xzf jdk.tar.gz`		# Decompress <code>tar -xzf jdk.tar.gz</code>
	# Move to a location you like `sudo mv jdk-11 /opt`		# Move to a location you like, e.g. <code>sudo mv jdk-11 /opt</code>
	# Add it to your path		# Add it to your path, e.g. <code>PATH=/opt/jdk-11:$PATH</code>

	= Simple Example Application =		= Simple Example Application =
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	</pre>		</pre>

	/dev/video1 is the device associated with the Raspberry PI camera.		/dev/video1 is the device associated with the Raspberry PI camera. You can now access it using Webcam Capture if you follow the instructions in the section [[#How do I get webcams to work?\| above]]

← Older revision		Revision as of 14:01, 26 May 2020
Line 10:		Line 10:
	# [[#Replacing Default Java\|Replace the JDK]]		# [[#Replacing Default Java\|Replace the JDK]]
	# [[Applications\|Download and Run Demonstrations]]		# [[Applications\|Download and Run Demonstrations]]

			{{#ev:youtube\|https://youtu.be/UdrCMB3josw\|400\|center}}