transformation

问题 I am working on a Open CV Android project, the aim is the user can take a picture of a snooker table and I have to find balls positions on image retrieved. When I have four corners of the table on my picture, it is pretty easy, I have already coded table, balls and colors detection, and I use getPerspectiveTransform() function to warp my table on a rectangle. Then I have balls center position on the rectangle. If I have three corners, I think I have to extend table edges and find lines

问题 I'm following some tutorials to learn openGL (from www.opengl-tutorial.org if it makes any difference) and there is an exercise that asks me to draw a cube and a triangle on the screen and it says as a hint that I'm supposed to calculate two MVP-matrices, one for each object. MVP matrix is given by Projection*View*Model and as far as I understand, the projection and view matrices are the same for all the objects on the screen (they are only affected by my choice of "camera" location and

问题 How can I calculate in MatLab similarity transformation between 4 points in 3D? I can calculate transform matrix from T*X = Xp , but it will give me affine matrix due to small errors in points coordinates. How can I fit that matrix to similarity one? I need something like fitgeotrans , but in 3D Thanks 回答1: The answer by @rayryeng is correct, given that you have a set of up to 3 points in a 3-dimensional space. If you need to transform m points in n-dimensional space ( m>n ), then you first

问题 In my application I've implemented a num-pad of my own, which is used for entering (number-based) passcodes. The 'password', or rather the 'dot'-representation of it, is shown on 4 EditTexts implemented in 4 boxes above the num-pad. When you enter a number one of those boxes will get filled in with a dot - for this I use the TransformationMethod PasswordTransformationMethod - but I'd want the number you punch in to be visible for a short while before it gets hidden (Like ~200ms). Is there any

问题 I have built a segmentation model using k-means clustering. Could anybody describe the process for assigning new data into these segments? Currently I am applying the same transformations/standardisations/outliers as I did to build the model and then calculating the euclidean distance. The minimum distance is the segment that record falls into. But, I am seeing the majority fall into 1 particular segment and I am wondering if I have missed something along the way? Thanks 回答1: Classifying a

问题 I can execute a independent scheduled transformation from pentaho DI server console . But, issue on running a parametrized scheduled transformation from pentaho DI server console .How can i pass parameter value at run time . In pentaho BI server , to execute parametrized report we used to pass variable value in URL . tried same in pentho DI server as below but didnt worked http:// * * /pentaho-di/kettle/transStatus?name=UI_parameter&Values=Testvalue 来源： https://stackoverflow.com/questions

问题 There are some looooong and hungry algorithms for doing so, but as of yet I haven't come up with or found anything particularly fast. 回答1: The fastest way is to this is to use unsafe calls to manipulate the image memory directly using LockBits . It sounds scary but it's pretty straight forward. If you search for LockBits you'll find plently of examples such as here. The interesting bit is: BitmapData originalData = originalBitmap.LockBits( new Rectangle(0, 0, originalWidth, originalHeight),

问题 I am working on a document processing application that generates and reads forms. The sample form attached is generated as a printed document, filled out by people, scanned and fed back to the application to detect filled values including Optical Marks (Bubbles), Text (OCR), etc. Click here for Sample Form. Since scanning distorts the image in terms of rotation, scale and translation, I use the three markers to detect orientation and correct the image in a rather primitive way that is VERY

问题 I have a package that sends out two emails whenever a control flow element fails. For example, if the ExecuteSQL Task fails, the Package level OnError event handler fires two emails. Is this a known issue? How do I get around this? I can do this through database driven scripts, but essentially, I would like to handle the situation on SSIS itself. Thanks for any help. 回答1: Keep in mind that event handlers will raise events anytime the triggering action occurs. So, you're not guaranteed to only

问题 I can't quite figure out how to do the following in one line: data(attenu) x_temp = attenu$accel^(1/4) y_temp = log(attenu$dist) best_line = lm(y_temp ~ x_temp) Since the above works, I thought I could do the following: data(attenu) best_line = lm( log(attenu$dist) ~ (attenu$accel^(1/4)) ) But this gives the error: Error in terms.formula(formula, data = data) : invalid power in formula There's obviously something I'm missing when using transformed variables in R's formula format. Why doesn't