The easiest and shortest: Way to do that in case when you dealing with UIImageView: Obj-C: theImageView.image = [theImageView.image imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate]; [theImageView setTintColor:[UIColor redColor]]; Swift: let theImageView = UIImageView(image: UIImage(named:”foo”)!.imageWithRenderingMode(UIImageRenderingMode.AlwaysTemplate)) theImageView.tintColor = UIColor.redColor()
You haven’t put the shared library in a location where the loader can find it. look inside the /usr/local/opencv and /usr/local/opencv2 folders and see if either of them contains any shared libraries (files beginning in lib and usually ending in .so). when you find them, create a file called /etc/ld.so.conf.d/opencv.conf and write to it the … Read more
Method #1: Structural Similarity Index (SSIM) To visualize differences between two images, we can take a quantitative approach to determine the exact discrepancies between images using the Structural Similarity Index (SSIM) which was introduced in Image Quality Assessment: From Error Visibility to Structural Similarity. This method is already implemented in the scikit-image library for image … Read more
For perspective transform you need, source points->Coordinates of quadrangle vertices in the source image. destination points-> Coordinates of the corresponding quadrangle vertices in the destination image. Here we will calculate these point by contour process. Calculate Coordinates of quadrangle vertices in the source image You will get the your card as contour by just by … Read more
If with “world coordinates” you mean “object coordinates”, you have to get the inverse transformation of the result given by the pnp algorithm. There is a trick to invert transformation matrices that allows you to save the inversion operation, which is usually expensive, and that explains the code in Python. Given a transformation [R|t], we … Read more
It appears that you’re using OpenCV version 3.x, while writing code intended for the 2.x branch. There were some API changes between those two branches. Since you’re using Python, you have a handy help available — make sure to use it, along with the documentation. OpenCV 2.x: >>> import cv2 >>> help(cv2.findContours) Help on built-in … Read more
Here the steps to use OpenCV 3.0.0 with precompiled libs, for a C++ project that links OpenCV statically, in Windows (tested with Windows 8.1) and Visual Studio (tested with Visual Studio 2013) to run this program: #include <opencv2\opencv.hpp> using namespace cv; int main() { Mat3b img = imread(“path_to_image”); imshow(“img”, img); waitKey(); return 0; } Download … Read more
The typical reason for 2+ USB cameras to not work together (still they might be working fine separately) is that USB bandwidth is insufficient for them both to run simultaneously. There is a bandwidth limit, which is rather low: The maximum throughput of an isochronous pipe (which is usually used for video) is 24MB/s. More … Read more
Note: I will explain the general principle and give you an example implementation in Python, as I don’t have the Android development environment set up. It should be fairly straightforward to port this to Java. Feel free to post your code as a separate answer. You need to do something similar to what the addWeighted … Read more
with opencv3.0, SURF/SIFT and some other things have been moved to a seperate opencv_contrib repo . you will have to download that, add it to your main opencv cmake settings (please look at the readme there), and rerun cmake/make. then: #include “opencv2/xfeatures2d.hpp” … Ptr<SIFT> sift = cv::xfeatures2d::SIFT::create(…); sift->detect(…);