I had a similar issue, and solved it using ImageMagics convert tool (http://www.imagemagick.org/script/index.php). That comes with linux and runs fine on Windows/Cygwin or OS X convert -density 300 largeVectorFileFromR.pdf out.pdf With -density 300 you control resolution (as DPI). Downside: Text is rasterized as well, I understand that Michael does not want this.
// Assumes myImage is the PNG you are converting using (var b = new Bitmap(myImage.Width, myImage.Height)) { b.SetResolution(myImage.HorizontalResolution, myImage.VerticalResolution); using (var g = Graphics.FromImage(b)) { g.Clear(Color.White); g.DrawImageUnscaled(myImage, 0, 0); } // Now save b as a JPEG like you normally would }
The images look pretty similar, but your eye can tell the difference, specially if you put one in place of the other: For example, you can note that the flowers in the background look brighter in the averaging conversion. It is not that there is anything intrinsically “bad” about averaging the three channels. The reason … Read more
You need to install Ghostscript in order to rasterize vector files (PDF, EPS, PS, etc.) with ImageMagick. IM will shell out to Ghostscript when doing these manipulations (you can see it if you use the -verbose tag in your IM invocation). You could also use Ghostscript by itself to rasterize vector files.