Archive for the ‘appjuice’ Category

openCV experiments

Monday, June 25th, 2012

Since we are currently not developing any new iOS game title we have some time to experiment with other things. Amongst others openCV on iPhone platform.

Because of the current ongoing EK soccer tournament we had our focus on football. More specifically tracking speed of a football. The concept is as follows:

Shoot a short video from somebody kicking a football (on a soccerfield), camera standing as perpendicular as possible to the assumed trajectory of the ball.

Then, based on the size of the ball in the videofootage as detected by openCV and the traveled ball distance from 2 frames in the video (recorded at a known time difference) in pixels. These pixel sizes recalculated to real life dimensions based on the known size of a typical football gives you the ballspeed. in kilometers/hour.

In theory this all sounds ok, but then we still have some practical issues to solve. First of all it turned out out that kicking the ball at fast speed (what real soccer players would do), skewed the ball enormously.

Skewed ball as caused by rolling shutter phenomenon

Skewed ball as caused by rolling shutter phenomenon

Here you can see some of the ball skewing

Here you can see some of the ball skewing. openCV "sees" the b/w filtered image

This is caused by rolling shutter artifacts see wikipedia. iPhone camera images are captured from top to bottom (landscape) line by line and not the whole frame at once. Because of this, a fast moving object will become skewed. openCV will not detect a circle when the circle is really skewed, so that’s the first problem.

Also when in low light situations, motion blurring, because of longer exposure times becomes an issue. The latest iPhone 4S support 1280×720 @60 fps which is the best bet when capping these frames. But even then motion blur can become an issue. Also ball detection is done based on the greenness of the grass. If your whitebalance is much to blue the conversion to black and white in opencv would fail. Of course you could adjust the tolerance for the detected hues but then you’re likely to run into many false positives for ball detections.

Much of these things/issues could have been fixed with some user input (let user select the correct ball, let user adjust filters for openCV based on some kind of wizard), but all in all it was a nice experiment but not good enough to make it into a proper dummy proof app. We basically didn’t want to make an app that expects all kinds of clever input from the user. We wanted the app to do some clever stuff and return you the speed of the ball without too much hassle.

opencv ball detection on the grass

opencv ball detection on the grass

Watermarker App update version 1.1 submitted to Apple

Tuesday, April 3rd, 2012
Main new feature fading

Main new feature fading

What’s New in this Version?

- Added watermark fading in and out options. With settable fade duration and fade – in/out point.

- Gui overhaul, changed the look of screen backgrounds and buttons. The glossy carbon look just didn’t cut it for me. I hope potential buyers agree with me it looks a bit more sophisticated now.

-Fixed some memory leaks

I hope it will be available soon, it has some nice added functionality. After this I will update CamLock with a bunch of extra features.

Text watermarking input screen

Watermarker app ready!

Friday, February 3rd, 2012

Watermarker app icon2 days ago our latest App Store iteration saw day of light on the App Store. It’s a video watermarker app which makes it pretty easy to imprint your logo or for that matter a small text into your video. When we created this we had journalists, bloggers in mind who create and deliver video content to a website or third party and are always using more or less the same watermark. Now its possible to create a fully montaged production in the field just using your phone. Shoot with our other app CamLock, brand the video with a text or image of choice (mail a transparent png to yourself save it to the photoroll and select it in the app) with the Watermarker app and you could use an app like iMovie to do some basic video montage. So there you go, just in time video delivery is finally there!

Tutorial video:

Bullet Time (The End of The World Party) in Dutch App Store

Wednesday, October 5th, 2011

Screen shot 2011-10-05 at 8.48.05 AM

So the day after laucnh we’re at position 33 in Category Adventure in Dutch App Store (for iPhone rankings ), we’re now beyond the legendary “Another World” and hope to climb up a few places still. So that’s it basically, the game has entered the App Store  at the same date as we set the availability date. This hepled us a little I think because we were nicely in view when sorted on release date, this was the case on every platform. So on the iPad we were in the last 12 released apps (no specific category!) and also in iTunes in recently released iPhone /iPad adventure and action games. Also in the GameCenter section, which I never visited before (oops). So hope sales will go strong for a couple of days, we’ll see.

Oh yeah just in case you want to buy Bullet Time too, here is the link to the App Store:

Bullet Time got approved!

Wednesday, September 28th, 2011


4 October, put it on your agenda people! Not only will Apple probably anounce their latest iteration of the iPhone at this beautiful day. But we at will launch our spectaculair iPad-iPhone game: “Bullet Time (The End of The World Party) ”

After a small misunderstanding about our GameCenter implementation, we appealed for a re-evaluation of the game and with success, we quickly got approved to the App Store. The release date is set at 4 October and we hope you will have a good time playing it.

BulletTime submitted (finally)

Thursday, September 15th, 2011
Waiting for review

Waiting for review

Yep, right now BulletTime is at Apple’s mercy, whether or not it will be approved for the App Store.

Right now we are waiting with high anticipation..

In the meantime we created a Gamecontrol demo, to show off the controls for BulletTime, we don’t use virtual joypads, instead movement is controlled using the accelerometer and only 2 buttons for jumping and shooting. Not tiny onscreen buttons, left half of the screen is jumping, right half is shooting, (Of course you can toggle that if you like that better).

Bullet Time Pre Release trailer

Tuesday, September 6th, 2011

Today we shot our trailer, we decided to use pure “in-game” footage for this trailer so people realy get to see what to expect from this game. In order to shoot this video we hooked our iPad up to an HDMI monitor and filmed that monitor with an iPhone using our own Camlock app. We decided to stick to 4:3 aspect footage because of the aspect ratio of an iPad which matches that ratio. The footage is not as clear as screengrabbed from the iPad simulator on a Mac, but because our game controls rely on the accelerometer and multitouch (shooting and jumping at the same time) playing on the simulator doesn’t work out.

So here it is: has been facelifted

Tuesday, August 30th, 2011

In order to accomodate the huge amount of traffic, because of our soon to be released iPad/ iPhone app title Bullet Time (The End of the World party),  to the support site, we have overhauled our website. It’s basically a sister site of which is more focussed on iOS development on private label instead of our work for third parties. So to say “Our own Stuff”. So check it out website website

Bullet Time (The End Of The World Party), action packed iPad platformer

Friday, July 29th, 2011


So we are back on Bullet Time (again). Our wall is currenlty completely covered in printed paper with 300 scenes of our biggest production yet.

We have made some political decisions on this game too. We have adapted the code so it runs on iPad and we liked playing it on the iPad so much that we will be releasing Bullet Time as an iPad only game. Later on the game will probably

be an universal game so people are also able to run it on their iPhones and iPods too. Right now we are progressing full speed and hope to be releasing pretty soon, with level design being completed (more or less) it’s now on to sound and scenery design.

Here are some caps to see what you might encounter in the game.


fig 1. Lonely meeting with Stryder, no ammo probably means you won’t make it alive to the next level


fig 2. Don’t be fooled by the many pickups, this is not going to be easy.


fig 3.  You were just strolling around in  concrete jungle when you run into JibberLeg..


fig 4. Sometimes when your own firepower just wont cut it, you have to rely on little tanky..

Bullet Time (on with the show)

Saturday, May 21st, 2011


So we’re level designing like there is no tomorrow (how appropriate), in this picture above you can see what our office-wall looks like right now. It’s covered with printed level schematics, nailed to the wall, so we are a bit able to keep track of the progress and also see in the blink of an eye (wel sort off) where which level is currently located in the game (and also by which name/id it goes). After purchasing 6.5 squaremetres of softboard we found out that we’re only half way yet ;-( So a lot of work needs to be done but we won’t give up on creating the most fatalistic game ever, oh no!!!