I want to implement red eye removal application on android. Is there any api or built in android method to do this? If no then please tell me how can we detect eyes from image? I know how to remove red color but Im having difficulty in detecting eyes from image.
Use the OpenCV to detect the eyes and then in the circular region where you expect the pupils to be, take the pixel value and set the Red value to, say, 20% of its original value while leaving the Green and Blue channels untouched.
There is also the FaceDetector.findFaces() which works for Bitmaps. However, it will just give you a Rectangle of the Face. But it should be easier to search in that rectangle for red-saturated pixels and desaturate the color as Alexander suggested. But this way you don't necessarly need another library.
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I am trying to use the Tap Target View library from GitHub in an android app.
https://github.com/KeepSafe/TapTargetView
I was wondering if anyone knows if we can use this library to highlight a rectangular shape or if it is primarily for targets that can be surrounded by a circle. I like to highlight an entire row in a list view.
Thanks
This library when reviewing the codes you find out there is no arc or circle in this customView and is a Rect...
So how is this circle like? It cause the radius number it gets. so if you know you can change the code very easily and remove or make the radius to 0.
But my question is why? really is going to make a bad mess for rectangular things...
I am working on chroma key (green screen) filter for android using opengl; the only difference is I am trying to replace not only green background but any color passed by user. I have been able to replace the color but the problem is that it also replaces color from object where light intensity is very high.
Can anyone help me to reduce the light glare from texture so that my filter can work as expected?
Or any reference greenscreen filter which works perfectly.
Anything will be welcomed.
EDIT : I have added screenshot to explain the situation, Here I tried to replace red background with these clouds, it worked for all area excluding the one having glare of light in it. I can overcome this by increasing the tolerance value but then that will make it to replace some yellow pixels from the object.
Algorithm wise just matching RGB colors is going to be difficult.
The first thing to note is that in your case you are really just looking at some form of luminance-sensitive value, not a pure chroma value. Bright pixels will always have a strong response in R, G, and B channels, so simple thresholding isn't going to give a reliable workarond here.
If you extracted a luminance-independent chroma value (like a YUV encoding would do) then you could isolate "redness", "greenness", and "blueness" independent of the brightness of the color.
However, this is still going to have edge cases. For example, what happens if your bottle is red, or has a red label? To solve this you need some form of geometry feature extraction (e.g. sorbel edge detect over the image), and then color replace only within a specific identified region.
None of this is trivial - accurate object detection and recognition is very hard and still very much under active research (e.g. think Tesla cruise control trying to spot and avoid objects while driving).
I am developing an app which will change the color of your eye. I need some help about detecting eye ball. Currently i have a selector that will be used to reduce ROI. It look like
this
So who we can detect eye ball from that selected region. I was thinking about changing the image to grayscale and then detect big black spot from that and then change color of it which will be the next step. i'll really appreciate any help.
Your way of thinking about a returning pattern is a good start. I am doing some work on a pattern recognition chair as well, so here is some help for your task:
using a grayscale is a good start btw ;)
There are some "facts" that are always applicable to a non pathologic eye:
the center is dark
left and right side surrounding dark ball are almost white (depends on how open the eye is)
do not forget: you have 2 eyes. link them together in some way (usually they are on an approximately horizontal line)
there is usually motion in the eyes while the other regions of the picture are relatively calm
Of course I cannot provide any code here, this would blast this whole post, but I hope I could help you in some way.
I found some link these guys detecting pupil of the eye. May b this will help you . See here and here
you could use the template matching method from open cv. template matching
this will help you find the eye in most of the cases.
Another solution would be to convert your image into an edge image with e.g. canny edge detector from opencv. and then search for this pattern with the template matcher. Using the edges makes you independent of the color. Using grayscale images will also facilitate the procedure.
What would be the best way to compare a gesture made on an Android device's screen with a stored gesture? For example, if in my application, I want it so that if I draw a triangle with my finger, the screen will turn blue, and if I draw a circle, the screen will turn red, how could that be done? The only thing I have been able to think of so far is to somehow generate an image file and then compare that to an image of a triangle or circle and check for similarities. But that wouldn't really account for different sized shapes or offset ones. Any ideas on how this could be implemented? Thanks!
There is no need to compare/match the shape of a gesture with an image. The better way is to mathematically guess which one of the recognized shapes did the user draw. http://developer.android.com/resources/articles/gestures.html provides a great reference for implementing gestures.
HTH,
Akshay
I need a graphical needle gauge (like a speedometer etc) for my app but such a UI widget is not part of the SDK so I probably have to create it myself.
My idea is to have the background with the tickmarks and coloured fields (green, yellow, red) as one bitmap and the needle as another bitmap drawn on top of the background, but rotated in the appropriate angle.
In my book, Professional Android 2 Application Development, there is a somewhat similar example with a compass rose, although that one is drawn using line graphics, not pre-fabricated images like I will have to use to get the desired look.
However, in the compass example the whole canvas is rotated before drawing the tick marks. I cannot use this approach as it will also rotate the gauge background. So I need to somehow rotate the needle image (which should be transparent) before superimposing it. But I don't know how to do accomplish this.
Can anyone lead me in the right direction on how to proceed with the needle gauge? Also, if there is a better way to build the meter than sketched above, please let me know.
You can divide your guage into different layers. One for background, one for tick marks. Layer for tick marks can be rotated to draw marks and when turned back and combined with 'background' layer.
You can see the following example with layer technique described above: http://mindtherobot.com/blog/534/android-ui-making-an-analog-rotary-knob/
P.S. This is not my blog, i've just found this technique there.