In OpenGL, matrices you specify are multiplied to the right of the existing matrix, and the vertex is on the far right of the expression. Thus, the last operation you specify are in the coordinate system of the geometry itself. (The first is usually the view transform, i.e. inverse of your camera’s to-world transform.) Bahbar … Read more
Here is how you implement a low-pass filter using convolution: double[] signal = (some 1d signal); double[] filter = [0.25 0.25 0.25 0.25]; // box-car filter double[] result = new double[signal.Length + filter.Length + 1]; // Set result to zero: for (int i=0; i < result.Length; i++) result[i] = 0; // Do convolution: for (int … Read more
I’m not a big fan of GUI builders: They typically autogenerate bucket-loads of code that then locks in your whole development team to using one IDE. Also, this code is often unreadable (check the code generated when using Matisse under Netbeans). My recommendations for GUI design / debugging would be: Add a main method to … Read more
I found I had to adjust Dmitri’s answer to ensure it works with images that don’t actually need cropping (either horizontally, vertically or both)… public static Bitmap Crop(Bitmap bmp) { int w = bmp.Width; int h = bmp.Height; Func<int, bool> allWhiteRow = row => { for (int i = 0; i < w; ++i) if … Read more
A synthesis of the answers to this post, the answers to Consty’s, and my own research: What works: Use GraphicsConfiguration.createCompatibleImage to create images compatible with what you’re drawing on. This is absolutely essential! Use double-buffered drawing via Canvas.createBufferStrategy. Use -Dsun.java2d.opengl=True where available to speed up drawing. Avoid using transforms for scaling. Instead, cache scaled versions … Read more
This is an 8-year-old question, but one that I recently struggled with, so I thought I’d share what I came up with. I spent a lot of time trying to use solution (9) from this article by Aleksas Riškus and couldn’t get any sensible numbers out of it until I did some Googling and learned … Read more
Refering to this, it can be solved by creating a blank bitmap with the same dimensions and the correct PixelFormat and the draw on that bitmap. // The original bitmap with the wrong pixel format. // You can check the pixel format with originalBmp.PixelFormat Bitmap originalBmp = (Bitmap)Image.FromFile(“YourFileName.gif”); // Create a blank bitmap with the … Read more
When you create the figure you set the Visibile property to Off. f = figure(‘visible’,’off’) Which in your case would be im = imread(‘image.tif’); f = figure(‘visible’,’off’), imshow(im, ‘Border’, ‘tight’); rectangle(‘Position’, [100, 100, 10, 10]); print(f, ‘-r80’, ‘-dtiff’, ‘image2.tif’); And if you want to view it again you can do set(f,’visible’,’on’)
If you are looking for a C++ library, then Qt basically does what you are looking for. If you want to stick to pure C, then Qt is not an option. As a C framework you could use GTK+, it works on Linux, Windows and OS X.
You should use setStroke to set a stroke of the Graphics2D object. The example at http://www.java2s.com gives you some code examples. The following code produces the image below: import java.awt.*; import java.awt.geom.Line2D; import javax.swing.*; public class FrameTest { public static void main(String[] args) { JFrame jf = new JFrame(“Demo”); Container cp = jf.getContentPane(); cp.add(new JComponent() … Read more