graphics

问题 I have been making plots for some time now, and they are precisely the way I like them, on screen. The data is coming in from sensors related to solar power collection and storage. Plotted on screen they look great so I do a screen region capture to save them. So now I would like to automate the saving process. Here is what I have done so far: I set up a cron job so they would be run right at midnight, capturing the whole day and saving it as a .png file Then it moves the "today.dat" data

问题 I've been playing with the optical flow functions in OpenCV and am stuck. I've successfully generated X and Y optical flow fields/maps using the Farneback method, but I don't know how to apply this to the input image coordinates to warp the images. The resulting X and Y fields are of 32bit float type (0-1.0), but how does this translate to the coordinates of the input and output images? For example, 1.0 of what? The width of the image? The difference between the two? Plus, I'm not sure what

问题 I've been playing with the optical flow functions in OpenCV and am stuck. I've successfully generated X and Y optical flow fields/maps using the Farneback method, but I don't know how to apply this to the input image coordinates to warp the images. The resulting X and Y fields are of 32bit float type (0-1.0), but how does this translate to the coordinates of the input and output images? For example, 1.0 of what? The width of the image? The difference between the two? Plus, I'm not sure what

问题 I've been playing with the optical flow functions in OpenCV and am stuck. I've successfully generated X and Y optical flow fields/maps using the Farneback method, but I don't know how to apply this to the input image coordinates to warp the images. The resulting X and Y fields are of 32bit float type (0-1.0), but how does this translate to the coordinates of the input and output images? For example, 1.0 of what? The width of the image? The difference between the two? Plus, I'm not sure what

问题 I've been playing with the optical flow functions in OpenCV and am stuck. I've successfully generated X and Y optical flow fields/maps using the Farneback method, but I don't know how to apply this to the input image coordinates to warp the images. The resulting X and Y fields are of 32bit float type (0-1.0), but how does this translate to the coordinates of the input and output images? For example, 1.0 of what? The width of the image? The difference between the two? Plus, I'm not sure what

问题 I've been playing with the optical flow functions in OpenCV and am stuck. I've successfully generated X and Y optical flow fields/maps using the Farneback method, but I don't know how to apply this to the input image coordinates to warp the images. The resulting X and Y fields are of 32bit float type (0-1.0), but how does this translate to the coordinates of the input and output images? For example, 1.0 of what? The width of the image? The difference between the two? Plus, I'm not sure what

问题 I'm looking for an O(n*logn) algorithm to find and print the intersections of n given circles. Each circle is specified by its center and radius. An O(n 2 ) algorithm consists in checking if the distance between the centers is less than or equal to the sum of the radii (of the two circles being compared). However, I'm looking for a faster one! A similar problem is intersection of line segments. I think even my problem can be solved using line sweep algorithm, but I am unable to figure out how

问题 I'm using TextRendere.MeasureText instead of Graphics.MeasureString because it allows me to specify TextFormatFlags.NoPadding, but its return width is a few pixels to wide. For a four character text string its five pixels over and for a five character text string its six pixels over. I'm sure its going to be even more with longer text strings. I'm using .Net 4.5.1. Here's my code: Size size = TextRenderer.MeasureText(items[a], new Font("Segoe UI", 12, GraphicsUnit.Pixel), new Size(Width, 15),

问题 so I have an AxisAngle4f object with a vector3D as axis and an angle, how do I get rotation angle for each of x,y,z axes? 回答1: create 4x4 homogenous transform matrix representing your rotation first see Understanding 4x4 homogenous transform matrices so basically you want 3 basis vectors and origin of unit matrix then rotate each by your rotation (for that you can use this or glRotate or whatever). Here C++ example: void rotate3d(float alfa,float *axis,float *point) { float p[3],q[3],c=cos