iOS Smudge effect

[SimonBS]

Hi.

First, I admit that I am definatly not that much into developing for the iPhone but I have been programming other languages for seven years which hopefully helps me udnerstand.

Some friends and I got a crazy idea for an app. What we need is some sort of a smudge effect which can be used on an image.

I've made a video of the ideal effect but something similar would also work.

You can find the video here.

I don't know if it's very advanced or if it can be done with not that many lines of code?

And that's why I ask here. Hopefully someone can give me a hint on how to do this or even show some code.

Don't take me wrong. I'm not asking you to make the app. I just wanna start developing applications and this was just a crazy idea which I would like to make real.

Thanks in advance.
Simon B. Støvring
Denmark

 

[HarryWorksInc]

sounds relatively hard

sound like it could take some fiddling around. I would try something like accesing the

-(void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event

and the
[/HTML]-(void)touchesMovedNSSet *)touches withEventUIEvent *)event {
[/HTML]

and try taking a picture of the place on the screen where the finger is and save it as where the finger was. Then when the picture moves put the picture where the finger is and take a picture again and save that as where the finger was and when the user moves his finger the whole thing starts over. I haven't actually tested this i don't know the exact result but its worth a try. I'm not promising results.

 

[SimonBS]

That is indeed ridning around. I'm not sure if that's the way to do it (of course, I asked the question to begin with) bu I'm very skeptIc about the result.
When searching for people looking for a function similar to mine - and believe me, there are not that many results - I read something about making a grid. Then there was a picture showing an image which looked smudged and with a grid on it.

 

[HarryWorksInc]

adding blur

I can imagine that it's hard to find people with similar needs as this. In the video you included the image looked not only "ridning around" but blurred and i think that that would help get the effect you are looking for. There is an apple sample code GLImageProcessing that shows an example of how to blur and maybe if you added the blur effect to each oncoming image you could get the effect shown in your video

 

[SimonBS]

There is an apple sample code GLImageProcessing that shows an example of how to blur and maybe if you added the blur effect to each oncoming image you could get the effect shown in your video

You see right. Maybe I should try making the blue effect on every image, hopefully I'll understand their example.
After all it will be one step closer the effect.

 

[HarryWorksInc]

ok

Ok Good Luck

 

[SimonBS]

Thanks. And thank for your help Of course, is anyone should have any hints or ideas, you are more than welcome to post a reply.

EDIT: This is what I was talking about when I was mentioning the grid. Actually it looks amazing. I just don't understand how to it (as mentioned, I'm new to iPhone programming and hoped to do this a fairly simple way) but someone might find this thread and find the grid solution useful.

Another way would be to use a grid approach - which is essentially an image rendered on a grid of quads and then get the desired effect by manipulating quad coordinates.
Given dense enough mesh, it works fine for all kinds of image transformations.

Here is an example ( using low res grid designed for a specific effect - you would have to use denser mesh)

http://www.warmi.net/tmp/Image.mov

http://www.iphonedevsdk.com/forum/iphone-sdk-game-development/36722-splatter-effect.html#post156451