Thanks for the comments Martin (and Jeremias). I ended up going with the oversized rendering and scaling down the resulting image. Interestingly, that too had surprising, unwanted effects - I was using Java 2d. Even testing on Gimp, using high quality scaling, the circle that overlaps four pixels evenly, when scaled down from 400 x 400 (or 100 x 100) pixels to 4 x 4 ends up with uneven intensities. I didn't investigate deeply but there must be some degenerate case with the interpolation when you get down to just a few pixels.
So I wrote my own scaling software. It considers my 400 x 400 image to be made of 4 "superpixels" that are 100 x 100. Then I get a single value for each of my superpixel (taking average intensity) and get a correct 4 x 4. Basic supersampling. Works well. Steve On Thu, Dec 22, 2011 at 4:42 AM, Martin J <jacobson.mar...@gmail.com> wrote: > FWIW, my experience is that regrettably, the HW/OS combo is key to the > image rendering quality; I had a servlet app I developed on Mac OS X > that produced SVG images on demand that had to be returned to the Web > client as PNG. On the Mac, the rendering was extremely good, but when > run on a PC/Linux server, it produced unacceptable images. In our > case, this issue was mostly that of poor text rendering at small type > sizes, due to bad anti-aliasing. After a lot of testing, we decided to > get a Mac dedicated to image rendering! YMMV. > best > Martin > > On 14 December 2011 16:01, Steve Maher <steve.f.ma...@gmail.com> wrote: > > Hi, > > > > I'm looking for a high-quality SVG renderer. Batik's rasterizer seems > to be > > the best out of the three I've tried, but I need it to do better. I've > > tried all the image-rendering, shape-rendering, color-rendering hints > > without much (any?) change. I've searched the source - mainly to try to > > increase any subsampling quantities - but had no luck. > > > > I'm dealing with small circles that need to be rendered "correctly" for a > > custom projector in our lab at work. > > > > For example, for a circle of radius .5 pixels (no stroke), and centered > in > > the middle of a pixel (in other words, a circle touching the edges of a > > pixel), the rendered pixel intensity should be roughly PI/4 times the > > intensity of the circle (because the ratio of circle area to square area > is > > PI/4). > > > > Also, if I rotate the circle by 45 degrees (rotation centered on corner > of > > pixel), there will be a 4 pixel square used to render the circle, with > most > > intensity split between two adjacent pixels and much less intensity split > > between the other two adjacent pixels. > > > > Batik comes close, but the intensity is high in the first case and in the > > second case, the intensity is not symmetric between the adjacent pixels > > (like the rotation wasn't exactly 45 degrees). > > > > One option I am exploring is to artificially enlarge the scene, render > by 1 > > pixel circle across, oh, 100 pixels, and then shrink the image. > Effectively > > increasing the subsampling of the circle to determine pixel intensity. I > > was hoping to be able to do that natively in the Batik source - or use > some > > other SVG renderer. > > > > Any tips are appreciated - > > > > Regards, > > Steve > > > > > > > > -- > From my MacBook Pro > > --------------------------------------------------------------------- > To unsubscribe, e-mail: batik-users-unsubscr...@xmlgraphics.apache.org > For additional commands, e-mail: batik-users-h...@xmlgraphics.apache.org > >
