The attached "examples.svg" is a SVG with a vertical line, and a polygone over that line, with an opacity of 0.7.
This looks fine in the Browser, but when it is rendered in Jasper Reports, (with SimpleRenderToImageAwareDataRenderer, but BatikRenderer makes no difference) there is no opacity and the borders of the polygone look very bad. (File: result-1)
I can get nice borders of the polygone by setting the opacity to 1.0, but well, no Opacity. then.. (File: result-2).