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Questions tagged [drawellipse]

51 questions
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1 answer

How to draw single-colour Ellipse (no black border) with QPainter

Code for the beginning: QColor yellow("#f0d048"); Qt::BrushStyle style = Qt::SolidPattern; QBrush brush(yellow, style); painter.setBrush(brush); painter.drawEllipse(10,10,10,10); Everytime I do this, I get a yellow circle surrounded by a black…
Aragon
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cv::Scalar not displaying expected color

On an image frame, I use void ellipse(Mat& img, Point center, Size axes, double angle, double startAngle, double endAngle, const Scalar& color, int thickness=1, int lineType=8, int shift=0) to draw an ellipse and I want to set the ellipse color to…
Protocole
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Transparent Ellipse

How do you draw a transparent ellipse with GDI? I tried SetBkMode() but I still get a white ellipse bk. case WM_PAINT: { hdc = BeginPaint(hwnd, &ps); SetBkMode(hdc, TRANSPARENT); // doesnt work Ellipse(hdc, 0,0,500,500); …
Geore Shg
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4
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Why doesn't drawing an ellipse with Pen::DashPattern set produce the expected result?

I'm trying to (simply) draw some lines rotating along an ellipse path and thought I had a nice easy way of doing it. Unfortunately, my solution seems to have some problems: void EllipseDisplayControl::OnPaint(PaintEventArgs^ e) { Graphics^ gfx =…
Jon Cage
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4
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2 answers

Making eyeball look at/follow cursor movement (C#)

I'm stuck here. I want to have the eyes drawn while 'looking' at (the angle of) the cursor. Also, it should be contained within the bigger circle/quadrant (just like an eyeball). Sadly, it just won't draw the eye for me at the right position/angle…
carrotcake
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4
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1 answer

Float parameters instead of int for new Rectangle() c#?

Is it possible to use as parameters float instead of int for the Rectangle class in c#?! Or any way in which I can do this by creating maybe a new class similar to Rectangle that takes as parameters float? I am trying to use this within the…
Bogdan Goie
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3
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3 answers

Ellipse representing horizontal and vertical error bars with R

In R, how to use ellipses to represent error bars (standard deviation) for x and y variables if only summary data, i.e. mean and SD for different data sets, are available. Any feedback is appreciated.
peanut
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How to detect ellipse and remove outliers in image using opencv Python

I'm trying to extract the dots that form an ellipse then draw it . But because of some points that can be considered as outliers, I got an invalid mask of ellipse. Like this: Here is the code that I'm executing, but it always selects the…
ELOUTMADI
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3
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1 answer

Drawing points of handwritten stroke using DrawEllipse (GDI+)

I'm working on an application that draws handwritten strokes. Strokes are internally stored as vectors of points and they can be transformed into std::vector. Points are so close to each other, that simple drawing of each point…
LihO
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2
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2 answers

How to draw circles faster on windows form?

I need to draw small circles at given X,Y coordinates but could be as high as 6000 circles on a panel on a window. How it is very slow and takes about 2 to 3 seconds for 5000 circles. How could I draw this faster? private void drawBGA_Pins(BGAmap…
PCG
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2 answers

How to convert ellipsoid to mesh3d in R?

I use the ellipsoidhull method from cluster package to obtain the minimum volume enclosing ellipsoid (mvee) from a set of points. This method returns an object of class ellipsoid. I need to plot the generated ellipsoid. I tried to use the wire3d…
m.taheri
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1 answer

Detecting an ellipse in a glaucoma photo

For glaucoma diagnosis it is common to determine a "cup to disk ratio" which compares the diameter of the optic disk (VDD) and optic cup (VCD). The optical disk is visible as a circular red feature (red channel) and the optic cup shows up as a…
indra ginanjar A.T
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How can I draw an ellipse based on four rotated and scaled points?

I start with a perfect circle, and then I need to rotate and scale it free without loose the ellipse characteristics: I would like to know if there is a way to describe a ellipse distorted like that based only in cosines and sines. I have this…
Carlos Oliveira
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Fill Ellipses with Gradiant Color on Matlab

I have a code on matlab that allows me to plot a series of ellipses, what I am trying to do it to fill each of them with a gradiant color based on 'arcsin(b/a)' The number will go from 0° (straight line) to 90° (pure circle). So each ellipse will…
Dorian Kartalovski
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1 answer

Superimpose ellipse on a simple X-Y plot in R

I have some data which I have plotted using plot(x,y,..) function. Now I want to superimpose three ellipse on this plot. I know the radius for every axis and I know the center for every ellipse.How can I create such ellipse in R. Not much help is…
Ved Gupta
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