gdi

It seems that .NET can't open JP2 (Jpeg 2000) files using the GDI library. I've searched on google but can't find any libraries or example code to do this. Anybody got any ideas? I don't really want to pay for a library to do it unless I have to.. Seems like we can do it using FreeImage (which is free) FIBITMAP dib = FreeImage.LoadEx("test.jp2"); //save the image out to disk FreeImage.Save(FREE_IMAGE_FORMAT.FIF_JPEG, dib, "test.jpg", FREE_IMAGE_SAVE_FLAGS.JPEG_QUALITYNORMAL); //or even turn it into a normal Bitmap for later use Bitmap bitmap = FreeImage.GetBitmap(dib); Rowland Shaw I was

I have a small paint program that I am working on. I am using SetPixel on a bitmap to do that drawing of lines. When the brush size gets large, like 25 pixels across there is a noticeable performance drop. I am wondering if there is a faster way to draw to a bitmap. Here is a bit of the background of the project: I am using bitmaps so that I can utilise layers, like in Photoshop or The GIMP. Lines are being drawn manually because this will eventually use graphics tablet pressure to alter the size of the line over its length. The lines should eventually be anti-aliaced/smoothed along the edges.

Is it possible to load a PNG from a file into an HBITMAP using Win32 GDI functions? If not, what would be the lightest solution without using external libraries (like libpng)? You can use the Windows Imaging Component to load PNG files (on Windows XP SP2 and later). See MSDN Magazine for an introduction on how to use the API and my blog post for a code sample that loads a PNG from an IStream and converts it to an HBITMAP. There is no need to use Windows Imaging Component, GDI+ or PNG library. You can use Icon functionality. Add new icon (ICO_PNG) to VC project resources with custom Width and

TextRenderer is based on GDI and Graphics.DrawString is based on GDI+.Which of these functions can deliver better quality text while drawing text on an image. Just my 2 cents: I always use Graphics.DrawString, except when I need to do custom painting for my (Windows Forms) controls. For example in a listbox that has OwnerDraw set, if I attach a DrawItem event handler that fully paints items, including item text. Or in a custom control I have to paint myself. In an application that uses Visual Styles on an OS that supports it and has it enabled, text drawn with Graphics.DrawString looks "off"

原文链接 : 2D Drawing APIs in Windows 背景知识 : Windows 图形编程 在 Windows 7 操作系统中，微软花费了很大的力气构建了一套新的 2D 绘图 API。我们称之为 Direct2D ，隶属于 DirectX 家族。这个 API 的开发填补了 Windows 图形平台的一些缺陷。其中非常重要的一点就是普通的 2D 程序渲染不再缺乏硬件加速。而在 Windows Vista 中，我们知道 GDI 是无法进行硬件加速的。微软寄望于开发的这个 API 具备很多现代特性。比如支持抗锯齿和 Alpha Blend 的 2D 渲染，和其它现代图形 API 交互，服务器端渲染，诸如此类。 为了方便理解微软为何开发 Direct2D ，我们先来回顾一下当初开发 Windows 时的历史。最初的渲染系统叫做 GDI (图形设备接口)，今天仍然存在。它最初为 16 位 Windows 写就，随后升级到 32 位 Windows (Windows 95 和 Windows NT)。因为 GDI 是为很久以前那些计算能力低下的计算机而开发的，所以它并没有诸如抗锯齿之类的特性，大多数 API 亦不支持 Alpha 通道。 在 Windows 95 期间，DirectX 发布了第一版。DirectDraw 是其中最早的组件之一。当初的本意是在硬件加速启用的情况下