gdi+

Outline of a text as single line vector path

由 落花浮王杯 提交于 2019-12-04 06:05:48
For an application I need to draw text/glyphs as a vector based path. Using GDI+ GraphicsPath and Graphics.DrawPath or WPF FormattedText and Geometry works fine and I get the output as shown in the first picture. But is it somehow possible to get letters as a single line path as shown in the second picture (shows an L). I'm glad if anyone has an idea. See this example. Using built-in function will always give you the path of a letter containing it's inner and outer borderline. Only the first one is made of single strokes which results in a much shorter path. drankin2112 Single stroke fonts

Clarification about how ColorMatrix transformations work

由 别等时光非礼了梦想. 提交于 2019-12-04 05:05:48
I'm doing some work on an image processing app (for fun) and am struggling to fully understand how ColorMatrix transformations work. I get the basics of linear/affine transformations, and can get by just fine by replicating examples online, but I'd like to fully grasp why something works instead of just being satisfied that it works. For example, doing a simple transformation on an image to produce its negative (each color is converted to its respective complimentary) uses the following matrix: [-1, 0, 0, 0, 0] [0, -1, 0, 0, 0] [0, 0, -1, 0, 0] [0, 0, 0, 1, 0] [1, 1, 1, 0, 1] I understand that

Bilinear interpolation - DirectX vs. GDI+

由 寵の児 提交于 2019-12-04 05:03:05
I have a C# app for which I've written GDI+ code that uses Bitmap/TextureBrush rendering to present 2D images, which can have various image processing functions applied. This code is a new path in an application that mimics existing DX9 code, and they share a common library to perform all vector and matrix (e.g. ViewToWorld/WorldToView) operations. My test bed consists of DX9 output images that I compare against the output of the new GDI+ code. A simple test case that renders to a viewport that matches the Bitmap dimensions (i.e. no zoom or pan) does match pixel-perfect (no binary diff) - but

C#: Is it necessary to dispose of a graphics element inside a custom control?

由 对着背影说爱祢 提交于 2019-12-04 04:46:10
问题 I've created a custom control, overridden it's paint event. When I try to dispose of the graphics I create they just disappear from the screen. Don't I need to use dispose in custom controls? EDIT: I've included a code snippet. Why can't i dispose the dc graphics object, created from the PaintEventArgs? Do i need to dispose it? class canvas : Control { PointF mouseDown; float newX; float newY; float zoomFactor = 1F; Graphics _dc; public canvas() { this.DoubleBuffered = true; mouseDown = new

Color Image Quantization in .NET

由 心不动则不痛 提交于 2019-12-04 04:21:07
问题 I want to reduce the number of unique colors of a bitmap in c#. The reason I want to do this is that an image which is initially created with three color but due to many factors (including compression) has now more than three colors (i.e neighbour pixels has affected each other) Any idea of how to do that? The solution maybe something to convert the whole bitmap from RGB to Indexed color system or some function that can be applied to a single pixel. Any GDI+ or Emgu (opencv) solutions are

Prevent RTL TListView from mirroring check boxes and/or graphics

由 旧城冷巷雨未停 提交于 2019-12-04 04:09:10
问题 I'm trying to make columns of a ListView appear from right to left. This has already been asked and answered. But the problem is about icons and check boxes. When I make a ListView RTL using SetWindowLong , it mirrors graphics and checkboxes as well, wich is not wanted. I can mirror graphics using editing tools, bothering but doable, but I don't know how to handle check boxes. I think both of them have same reason, so I searched about it and found an entire article about RTL layout in

How can I extract a specific Image from an Icon file in .NET?

由 江枫思渺然 提交于 2019-12-04 04:05:30
问题 Icon files (*.ico) may contain multiple images at different sizes and of different colour depths. How can I obtain a System.Drawing.Image object from a .ico file? One option is Image.FromFile(...) , but for icon files with multiple images there is no way to specify which image size and colour depth to return. Ideally the solution would use only managed code, but I'm happy to hear about interop calls to Win32 functions as well. 回答1: Simple answer to all your questions: IconLib 回答2: System

How to Set this Kind of Perspective Transform in Matrix3D?

由 此生再无相见时 提交于 2019-12-04 04:04:21
I have an image with and have a few values to make it a perspective in Silverlight, but can't quite figure out what I need to do mathmatically to make it happen. The most important thing is I have an angle called a "Field of View" ( FOV ). This is the normal picture: For example: X = 30° X = 30° X = 30° FOV = 30° FOV = 60° FOV = 120° X = 60° X = 60° X = 60° FOV = 30° FOV = 60° FOV = 120° Any help would be appreciated to walk me through the math to reproduce these in Silverlight. I think the problem everyone is encountering is that there needs to be a viewport shift along with the perspective

Access violation in Image destructor

由 旧时模样 提交于 2019-12-04 03:59:40
问题 A very simple program I might say.. #include <windows.h> #include <gdiplus.h> using namespace Gdiplus; int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE, LPSTR cmdLine, int nShow){ // Gdiplus variables GdiplusStartupInput mGdiplusStartupInput; ULONG_PTR mGdiplusToken; GdiplusStartup(&mGdiplusToken, &mGdiplusStartupInput, NULL); Bitmap bitmap(L"left.bmp"); GdiplusShutdown(mGdiplusToken); return 0; } When running this example I get an access violation in GdiplusBitmap.h in this function inline

How to draw ARGB bitmap using GDI+?

由 依然范特西╮ 提交于 2019-12-04 03:42:12
问题 I have valid HBITMAP handle of ARGB type. How to draw it using GDI+? I've tried method: graphics.DrawImage(Bitmap::FromHBITMAP(m_hBitmap, NULL), 0, 0); But it doesn't use alpha channel. 回答1: I've got working sample: // 1. Get info using bitmap handle: image size, bits BITMAP bmpInfo; ::GetObject(m_hBitmap, sizeof(BITMAP), &bmpInfo); int cxBitmap = bmpInfo.bmWidth; int cyBitmap = bmpInfo.bmHeight; void* bits = bmpInfo.bmBits; // 2. Create & draw new GDI+ bitmap using bits with pixel format
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