Image is an abstract class: what you want to do depends on whether you are dealing with a Metafile or a Bitmap. Creating an image with GDI+ and saving it as an EMF is simple with Metafile. Per Mike’s post: var path = @”c:\foo.emf” var g = CreateGraphics(); // get a graphics object from your … Read more
WinForms (and underlying User32) does not support transparency at all. WinForms however can simulate transparency by using control style you provide – SupportsTransparentBackColor, but in this case all that “transparent” control does, it to allow drawing parent its background. ButtonBase uses some windows styles that prevent working this mechanism. I see two solutions: one is … Read more
The problem is int center = radius which you are setting int radius = 576. This doesn’t make sense as surely you are rotating about a point that should have an x and y location. Given you are rotating around the origin the center x and y should both be 0 not 576. So, given … Read more
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);
Yes, it is too slow. I ran into this problem several years ago while developing Paint.NET (right from the start, actually, and it was rather frustrating!). Rendering performance was abysmal, as it was always proportional to the size of the bitmap and not the size of the area that it was told to redraw. That … Read more
When drawing a string of characters (ASCII or a form of Unicode encoded symbols) using Graphics.DrawString() with a fixed sized Font, the resulting graphics appear to generate a sort of grid, degrading the visual quality of the rendering. A solution is to substitute the GDI+ Graphics methods with the GDI methods, using TextRenderer.MeasureText() and TextRenderer.DrawText(). … Read more
Use Processes. GDI+ blocks per process a lot of ways. Yep, a pain, but there’s no way around it. Fortunately with tasks like this one (and any one that processes files on the filesystem), it’s too easy to just split the workload up between multiple processes. Fortunately it looks like GDI+ is using locks, not … Read more
I went through the same journey as a few other posters on this thread. Things I noted: Using Image.FromFile does seem unpredictable on when it releases the file handle. Calling the Image.Dispose() did not release the file handle in all cases. Using a FileStream and the Image.FromStream method works, and releases the handle on the … Read more
i’m going to cross-post my answer from over here, just so that the information gets around. There are two ways of drawing text in .NET: GDI+: graphics.MeasureString and graphics.DrawString GDI: TextRenderer.MeasureText and TextRenderer.DrawText In .NET 1.1 everything used GDI+ for text rendering. But there were some problems: There are some performance issues caused by the … Read more
There is a simpler way to flip a Graphics object. Create a Matrix which is the result of the Matrix multiplication of all the transformations that need to be applied to the specified object. A Matrix transformation can be applied to either the GraphicsPath object or the Graphics object. Or both, when multiple transformation need … Read more