Transformation of 3D objects related to vanishing points and horizon line

This is nowhere near my cup of tea so handle with extreme prejudice and also far form solution just some start point hints… First of all we need to define some constraints/assumptions in order to make this to work. user selects 4 lines representing 2 perpendicular planes and these 2 QUADs have the same height … Read more

How to recognize rectangles in this image?

Opencv (image processing and computer vision library written in c) has implementation for hough transform (the simple hough transform find lines in an image, while the generalized one finds more complex objects) so that could be a good start. For the rectangles which do have closed corners there are also corner detectors such as cornerHarris … Read more

Creating a Movie from a Series of Plots in R [closed]

Here is one method I found using R help: To create the individual image frames: jpeg(“/tmp/foo%02d.jpg”) for (i in 1:5) { my.plot(i) } To make the movie, first install ImageMagick. Then call the following function (which calls “convert”, part of ImageMagick I suppose): <- function(){ unlink(“plot.mpg”) system(“convert -delay 0.5 plot*.jpg plot.mpg”) } Or … Read more

Why doesn’t hue rotation by +180deg and -180deg yield the original color?

In both CSS and SVG filters, there is no conversion into HSV or HSL – the hueRotation shorthands are using a linear matrix approximation in RGB space to perform the hue rotation. This doesn’t conserve saturation or brightness very well for small rotations and highly saturated colors – as you’re seeing. A true hue rotation, … Read more

How to print R graphics to multiple pages of a PDF and multiple PDFs?

Did you look at help(pdf) ? Usage: pdf(file = ifelse(onefile, “Rplots.pdf”, “Rplot%03d.pdf”), width, height, onefile, family, title, fonts, version, paper, encoding, bg, fg, pointsize, pagecentre, colormodel, useDingbats, useKerning) Arguments: file: a character string giving the name of the file. For use with ‘onefile=FALSE’ give a C integer format such as ‘”Rplot%03d.pdf”‘ (the default in that … Read more