Summary
One not always have a measure ribbon in the pocket to asses which ball wins the point , in a 'petanque' or simply called 'ball game'.
Using a feet is not precise and your opponent may argue you are trying to move a ball ;-) So why not using your Android smartphone to measure the
distance in a few seconds?
Moreover ,only one measure suffices whereas 2 are required in reality.
Features
Manual ball/jack distance measurment , in either realtime camera mode ( faster ) or photo mode ( more accurate ).
Inclination indicator , using smartphone accelerometer.
Installation
Installs as a standard Android Market application. It will use the active locale ( French or English available ).
Usage
Startup
Once downloaded from the market , click on the gray ball icon..
Camera configuration
With Android 2.0 and above , this is not required. Otherwise , you may have to select the suitable definition for your camera device , as described here.
Measurment ( Quick mode )
That's straighrforward, just bend over the jacket and look at the camera image , with a circular ruler drawn on top of it.
Remarks:
- The ruler precision ( number of circle ) can be configured with the button which image has circles on it.
- Seldom , you may need to add some offset to the ruler ,while keeping circle spacing. Just sweep the screen horizontaly with your finger to achieve this.
- There is also a one circle mode , to adjust the circle like a tangent line.
- Settings will be memorised for the next use.
Measurment ( Eagle eye mode )
Most of the time , the quick mode will suffice to rank the balls. If that's not the case, a photo can help if :
- You need a much higher precision.
- Balls are located on the same side of the jack , and quite far from it.
- Senior players may have the difficulty keeping the jack aligned while reading the ruler. A photo will let them adjust witht needing to stay still while aiming at the jack.
From the 'quick mode' which is the default screen when you open the application , click on the camera icon ( top right corner ) after aiming at the jack.
Center it as much as you can , you will be able to fine tune with the photo.
Stand on top of the jack so that the photo does not have perspective errors. Freeze , and take the picture by either a click the touchscreen or a click on the big , general purpose smartphone button.
You should now see the photo in background . By default , non bouton is active , which means you will drag the closest object to you finger.
Although that usually enough , peoples with thick fingers will appreciate using boutons to do select the right item to adjust.
That is what we are going to explain now. Click on the top left icon ( cross shaped ).You are in the mode 'aim at the jack' , so the top left icon with a cross should be activated ( white ). Aim at the jack's center using either the touchscreen with you finger or the cursor keys around the general purpose button (Or the corresponding icon located on the bottom right corner of the screen). Using the touchscreen is however by far the best user experience.
Once the cross looks aiming at the center , you can still improve precision , if you like. Switch to zoom mode pressing at the smartphone general purpose button ( Or bottom right corner icon , as you like). With any of left hand side icon activated , this button swtiches back and forth between zoom mode and
translation mode. The active mode is visualized by either 4 arrows ( translation ) or a google pair ( zoom ).
Once in zoom mode , you can know zoom with left/righ cursor keys. Switch to translation again and improve cross alignment with the jack. When satisfied,
unzoom to approximately the initial photo size.
Now that you've just set one extremity of the measure ribbon , click on the icon to set the second extremity. That is the one with an arc and an arrow.
Expand the circle utill you reach a ball , that will be the ball winning the point. This work exactly as before . You can use finger or buttons , and translation or zoom. Note that you see a small red 'x' on the circle. This is the point you are actually dragging when adjusting the circle. This helps understanding
visually what happens when you are adjusting an item.
If you like numbers , you can see distance in pixel units in the bottom left cornet. That is however not required to know which ball wins.
The last icon we did not spoke about allows to move a third fictive point which is the center of the picture. You can optionaly use it to look at the scene
ar different points of interest.
Remark:
This measurment system also has the advantage of allowing to readjust a measure point ( the jack for instance ) without modifying the position
of the second measurement point ( the tangent ball for instance )
Inclination gauge
Make your measures even more accurate checking you are taking your measure with your phone perpendicular to the ground.
Several visual models included!
Select the drawing you like through the menu button . Select ' Gauge' , click on the button that opens a list. Select one, click ok and you are done!.
Score Management
From the handset menu, select 'Score'. A predefined team list will show up. Choose one on them for your team and udpate your score with the '+' and '-'
buttons. You may reset it to 0 using the button at the bottom.
Telemeter
Is the jack too close ? This is the question this tool will help you to sort out.
For the first measurement , the phone needs to know the vertical distance between the phone and the ground.
Press the icon with 2 arrows , and sweep the screen with your finger to adjust the height. Hold the position 2 seconds to validate.
Then , lift your phone in front of your face and aim at the target object , pointing at the contact point between the object and the ground. You must stand on
an horizontal surface for maximum accuracy.
Notice that if you slightly move the camera , it will significantly affect the measure. To fix this , this telemeter features a magnifier so that you can:
- Ajust the bounding rectangle around the target object to zoom.
- Adjust the screen size of the magnifier.
This is very intuitive , you just have to sweep the screen with your finger , either horizontaly or verticaly, to adjust either of the 2 parameters.
With legacy phones , ( Android system 1.5 or 1.6 ) , this feature may be unstable , due to lack of memory. Its advisable then to only use a small
size for the magnifier , in order to use less memory / cpu.
The magnifier may be disabled by sweeping the screen to the left ( portrait mode ).
Measurment accuray depends on:
- Handsdet accelerometer quality.
- Target measurment angle. ( This is a mathematical limitation of the algorithm ) The farther the object , the worse is the accuracy.
- How much care is taken to measure the distance.
Your body height is an approximation of the value required, since its the distance camera/ground which matter. Also do no forget that if
you hold your hands far from your body , your are measuring the distance from the object to your hands, and not to your feet.
You may offset those errors by adjusting the height value until you get the correct value for a distance that you know by advance.
Also, try to have the same posture while measuring.
As an example, a 5 cm precision measure could be achieved with LG optimus phone, at a 1.52m ground altitude , aiming at a target distance from 3.78 m.
On this phone , precision was much better in landscape mode than in portrait mode ( +20cm accuracy )
A good phone calibration may also help . A bespoke method is to move your phone along a '8' shaped path , with the phone screen facing the ground.
This should be done with ample , slow motion in a location free of intense magnetic fields.
About quality
- This application is spyware free , ads free.
- Small memory footprint .
- For Android 1.5 and higher.
- Measure accuracy depends on your smartphone. A relatively old smarphone with 480*320 pixels, provides a theoretical accuracy of 2 millimeter ( horizontaly ) , ignoring small deformations introduced by the camera lens. If like some french people you drink too much 'Pastis' while playing, precision
may decrease dramatically. ;-)