while in graduate school for biomedical eng I developed a device we called a "vein finder". It was a simple device that was good enough for our eng school to patent.
I think it would be very very easy to use the iphone camera to develop an iphone app whereby MD's/ nurses/EMT's could use the app to easily identify peripherial veins that are not visible to the naked eye. This would be invaluable in starting IV's and giving bedside medications. The vein finder was esp helpful for patients in shock who had poor venous filling and therefore didn't have veins that "popped into view" with a tourniquet.
It would require using the iphone light at specific wavelengths... anybody have any idea if that is possible?
I don't think you have any control over the flash light that illuminates images. You can only turn it on and off. I also doubt you would be able to get the specific wavelengths you need.
My suggestion would be to look into building a peripheral light device which plugs in to the headphone jack for power and has the necessary functions for emitting light at different wavelengths. That way, you would be able to get the exact result you require.
You may also need to look into the camera itself, as it may not have the ability to capture the light at the wavelengths you may require. Hope that Helps!
Do you mean overlaying veins over the picture on the camera? It would be easy if the veins are always in the same place... What would your imagined procedure be for using this app?
EDIT: You can not manipulate the iPhone light for different frequencies; you can only turn it on and off. You would need to get a separate external light for that.
To work around the fact that you can't set the wavelength of the built in light, you should use an external light along with the iOS device.
Apologies for massive necro!
The LED light of the iPhone is not the problem - most white light sources contain IR or near-IR (in fact they are made up from the entire visible spectrum). Daylight works very well too.
The problem is the receiver. Most camera lenses, including smartphones, have an IR filter - thus cutting out the useful part of the spectrum. All we need is a digital camera with IR filter removed, that has a viewfinder (where you'll see the veins).
Related
I built my unity game through Xcode into an iOS device for testing, and the colors look duller and more pastel-like than in the game view in the editor. The exact same thing has also happened on a modern android device. How can I make it so that the colors as seen in the built game better reflect the colors in the editor?
EDIT: I have sent a file to my phone and found out that the phone perceives colors differently than my monitor. I'm sorry if I'm asking for quite a bit here, but... is there any way to make the game look as I intend it to? The fact that I never see exactly how my game will turn out seems kinda... awkward. Thanks.
I'm not sure if you already tried this, but you might want to use Unity Remote for your iOS device, so you can check the color differences in real time instead of having to build it every time.
But other than what the comments said, it sounds like you should try to adjust your monitor's display settings for better color correlation between the built game and the one in the editor.
What should I do if the compass on two or more different devices give me different headings? I tried to calibrate the compass on devices but anyway sometimes they show me differents headings.
Since the iPhone compass "works just like a magnetic-needle compass":
The accuracy of digital compass headings can be affected by magnetic or other environmental interference, including interference caused by proximity to the magnets contained in the iPhone earbuds. The compass may need to be calibrated from time to time (Apple: iPhone and iPad: Calibrating Compass).
You have several options for fixing the compass:
Follow the directions! Move the device in a figure eight motion. However, this looks like it isn't working for you.
"[d]isregard the message to calibrate". Some areas have more magnetic interference than others, like in a car because of its dashboard. You can just leave it alone because "[t]he device will eventually recalibrate after several turns. Note that it may need to periodically recalibrate while you are driving, depending on the level of magnetic interference present."
Reboot (Not the "Slide to Power Off" reboot). Hold the power button and home button until the Apple logo appears.
I'm pretty sure those are your options. There may be more, so I'll do more research.
If you just want to see which compass is wrong, get a real compass and compare it to the headings on the two iPhones. Which ever one it matches up with, the other phone is wrong. If you don't have a real compass, you can follow this tutorial to make a homemade one (which is more fun)!
Hope this helps!
Well, if 2 iOS devices give you 2 different readings then at least one of them has uncalibrated hardware. So is this a hardware question? I don't think there is much to do in terms of the program, especially if you have no idea what the exact skew is.
I am working in an AR project, and we want to manipulate the focusing distance of the iPhone4 camera. Is this even possible? So far, we've found just toggling and auto focusing as options listed here : http://developer.apple.com/library/ios/#documentation/AVFoundation/Reference/AVCaptureDevice_Class/Reference/Reference.html%23//apple_ref/occ/instm/AVCaptureDevice/isAdjustingFocus
Thanks in advance for any tips! :)
Regarding the API it seems that the only supported actions are:
- check if AF is supported on the device (iPhones 3GS an 4 only I think)
- enable/disable AF
- set the point-of-interest that is NOT the distance, but only a point in the camera view.
Certainly not what you want to do.
Might be supported in private API... but that would not pass the validation process.
A workaround might be to see how much pixels move as the user shifts slightly, to get a sense of how distant some parts of the image are, and then set the AF point to a region of the image either closer or further based on that.
But, also file a Radar ticket requesting access to specify the focus distance if possible - if enough people ask Apple will add it to the API.
I want to adjust the exposure of the iPhone/iPod touch camera with intimate detail. I would prefer to take a series of photos with decreasing exposure times to obtain a sequence of images (for HDR reconstruction). Is this possible?
If not, what's the next best thing? It seems you can set a point of interest in the image for the autoexposure. Perhaps I could search for a dark/light region of the image and then use this exposurePointOfInterest to adjust the exposure, but this seems like a very indirect solution that is also error-prone. If anybody has tried an alternative, such an answer is also desirable.
As iOS gives control of frame durations by
MinFrameDuration
MaxFrameDuration
since exposure times vary based on fram rate and frame duration
By setting min and max frame rate to a particular value
You will be locking the fram rate.
That will effect your exposure times.
This is also very indirect way of controlling, may be it helps your case
some example would be like this:
if (conn.isVideoMinFrameDurationSupported)
conn.videoMinFrameDuration = CMTimeMake(1, CAPTURE_FRAMES_PER_SECOND);
if (conn.isVideoMaxFrameDurationSupported)
conn.videoMaxFrameDuration = CMTimeMake(1, CAPTURE_FRAMES_PER_SECOND);
Since you would have to decrease the shutter speed of the camera, this unfortunately does not appear to be possible, and more importantly, against the HIG:
Changing the behavior of iPhone external hardware is a violation of
the iPhone Developer Program License Agreement. Applications must
adhere to the iPhone Human Interface Guidelines as outlined in the
iPhone Developer Program License Agreement section 3.3.7
Related article Apple Removes Camera+ iPhone App From The App Store After Developer Reveals Hack To Enable Hidden Feature.
If it can be done programatically, instead of with the hardware, you might have a chance, but then its just an effect on an image,not a true long exposure picture.
There are some simulated slow shutter apps that do get approved like Slow Shutter or Magic Shutter.
Related article: New iPhone Camera App “Magic Shutter” Hits The App Store.
This is supported since iOS 8:
http://developer.xamarin.com/guides/ios/platform_features/intro_to_manual_camera_controls/
Have a look at AVCaptureExposureModeCustom and CaptureDevice.LockExposure...
I tried to do this for my motion activated camera app (Pocket Sentry) and I found that it is not possible to do this AND get approved in the app store.
I have been trying to do this myself. I think its possible only by using the exposure point of interest property. I am detecting the dark and bright spots and then adjusting the point accordingly.
Please refer : Detecting bright/dark points on iPhone screen
Does anyone know a better way to do this?
I am not too sure, but you should try using AVFoundation class to build the camera app, following the apple's sample code:
AVCam Sample Code
And then try to leverage the exposureMode property of the Class:
exposureMode Class Reference
I saw at least 6 apps in AppStore that take photos when detect motion (i.e. a kind of Spy stuff). Does anybody know what is a general way to do such thing using iPhone SDK?
I guess their apps take photos each X seconds and compare current image with previous to determine if there any difference (read "motion"). Any better ideas?
Thank you!
You could probably also use the microphone to detect noise. That's actually how many security system motion detectors work - but they listen in on ultrasonic sound waves. The success of this greatly depends on the iPhone's mic sensitivity and what sort of API access you have to the signal. If the mic's not sensitive enough, listening for regular human-hearing-range noise might be good enough for your needs (although this isn't "true" motion-detection).
As for images - look into using some sort of string-edit-distance algorithm, but for images. Something that takes a picture every X amount of time, and compares it to the previous image taken. If the images are too different (edit distance too big), then the alarm sounds. This will account for slow changes in daylight, and will probably work better than taking a single reference image at the beginning of the surveillance period and then comparing all other images to that.
If you combine these two methods (image and sound), it may get you what you need.
You could have the phone detect light changes meaning using the sensor at the top front of the phone. I just don't know how you would access that part of the phone
I think you've about got it figured out- the phone probably keeps images where the delta between image B and image A is over some predefined threshold.
You'd have to find an image library written in Objective-C in order to do the analysis.
I have this application. I wrote a library for Delphi 10 years ago but the analysis is the same.
The point is to make a matrix from whole the screen, e.g. 25x25, and then make an average color for each cell. After that, compare the R,G,B,H,S,V of average color from one picture to another and, if the difference is more than set, you have motion.
In my application I use fragment shader to show motion in real time. Any question, feel free to ask ;)