njaa's profile - activity

Hi,

I try to calibrate the stereo camera of my Evo 3D. Therefore I use the stereo_calib.cpp sample and a set of stereo images:

Left:

Right:

Result:

But as you can see the result is weird. When I use the sample images everything works fine:

Somebody can tell me what I'm doing wrong? The images are of size 270x480 while the sample images are 480x640. Could this be a problem? And of course the quality of the second image is worse (HTC Evo problem). But for me it seems there is a general problem. Please help :)

Hi,

I have a binary image and I would like to determine the amount of white pixels along different angles. Let`s say the starting Point (F) is at the middle of the bottom row. Based on this 0° means all white pixels to the right of F and 180° means all white pixels to the left of F in the bottom row. So at the end I would like to have a histogram with x-axis holding the angle (from 0 to 180) and y-axis the number of white pixels.

Is this possible with the OpenCV calcHistogram function? Or do you have any idea how to do this efficiently?

Hope you understand the problem since I`m not allowed(?) to attach images here.

Thank you.

push :)

No Computer Vision experts here?

I had the same errors, but I don't know anymore how I solved it.

But these are my current settings which do work:

In the Project Properties:

• Android -> Add the OpenCV Library
• C/C++ build -> build command -> ${NDKROOT}/ndk-build (in Windows it's ndk-build.cmd I think)
• C/C++ -> Environment -> add NDKROOT

• C/C++ General -> Paths and Symbols -> Add the following:

  1. ${NDKROOT}/sources/cxx-stl/gnu-libstdc++/libs/armeabi-v7a/include
  2. ${NDKROOT}/sources/cxx-stl/gnu-libstdc++/include
  3. ${ProjDirPath}/../../sdk/native/jni/include
  4. ${NDKROOT}/platforms/android-9/arch-arm/usr/include

Hi,

I would like to generate the birds eye view of an input image (given as Mat) with OpenCV. The intrinsic and extrinsic parameters of the camera are known.

Among other things I need to know the Viewpoint of the camera (l,h,d) and the viewing direction:

IPM.jpeg

So my question is how can I determine these parameters with the help of the known intrinsic and extrinsic parameters? Or have I to measure them otherwise?

Thank you.

Anybody out there who can use the native camera with HTC one X?

Edit: Using the Optimus 3D doesn't work as well. Though there is no error message, but the screen stays black...

I try to run one of the Sample Projects which uses the native Camera (e.g. Tutorial 2) with the HTC One X but it does not work. The following line:

mCamera = new VideoCapture(Highgui.CV_CAP_ANDROID);

in the code provides following log:

07-14 16:41:19.250: D/OpenCV_NativeCamera(17420): Supported Cameras: (null)
07-14 16:41:19.250: D/OpenCV_NativeCamera(17420): Supported Picture Sizes: 320x240,480x480,640x368,640x480,800x600,1024x768,1280x720,1280x752,1280x960,1440x1080,1600x1200,1836x1080,1920x1080,2048x1152,2048x1360,2048x1536,2592x1456,2592x1520,2592x1920,2592x1944,2592x1952,3264x1840,3264x2448
07-14 16:41:19.250: D/OpenCV_NativeCamera(17420): Supported Picture Formats: jpeg,jfif,exif
07-14 16:41:19.250: D/OpenCV_NativeCamera(17420): Supported Preview Sizes: 176x144,320x240,352x288,480x480,640x480,704x576,720x408,720x480,720x576,768x432,800x448,960x720,1280x720,1280x752,1360x720,1920x1080,1920x1088
07-14 16:41:19.250: D/OpenCV_NativeCamera(17420): Supported Preview Formats: yuv420p,yuv420sp
07-14 16:41:19.250: D/OpenCV_NativeCamera(17420): Supported Preview Frame Rates: 5,8,10,15,20,24,25,30
07-14 16:41:19.250: D/OpenCV_NativeCamera(17420): Supported Thumbnail Sizes: 0x0,320x240
07-14 16:41:19.250: D/OpenCV_NativeCamera(17420): Supported Whitebalance Modes: auto,incandescent,fluorescent,warm-fluorescent,daylight,cloudy-daylight,shade,twilight
07-14 16:41:19.250: D/OpenCV_NativeCamera(17420): Supported Effects: mono,negative,none,posterize,sepia,aqua,solarize,nv-vivid,nv-emboss
07-14 16:41:19.250: D/OpenCV_NativeCamera(17420): Supported Scene Modes: auto,action,portrait,landscape,beach,fireworks,night,night-portrait,snow,sports,steadyphoto,sunset,theatre,barcode,candlelight,beauty-mode,background-blur,backlight-hdr,close-up,white-board,flowers
07-14 16:41:19.250: D/OpenCV_NativeCamera(17420): Supported Focus Modes: auto,infinity,macro,fixed,continuous-video,continuous-picture
07-14 16:41:19.250: D/OpenCV_NativeCamera(17420): Supported Antibanding Options: off,auto,50hz,60hz
07-14 16:41:19.250: D/OpenCV_NativeCamera(17420): Supported Flash Modes: auto,on,off,torch,red-eye
07-14 16:41:19.260: D/OpenCV_NativeCamera(17420): initCameraConnect: autofocus is set to mode "continuous-video"
07-14 16:41:19.260: D/OpenCV_NativeCamera(17420): initCameraConnect: preview format is set to yuv420sp
07-14 16:41:19.260: A/libc(17420): **Fatal signal 11 (SIGSEGV) at 0x0000000c (code=1)**

I tested several other device and they curiously work. How can I solve this?

My device: HTC One X (Tegra 3), OS Version 4.0.3

The problem is that the redirection to the Play Store doesn't work ("Item not found"). So I cannot let the Manager download the latest package and I have to search for it manually. I'll try the neon-package then, thx

Thanks for the answer. Yes, I have installed the same apps now. The sample projects which do not use native camera work for me, just tutorial 2, facedetection, puzzle-15, etc. crash :/