Re: Down sampling guidance for raster content in SVG.

Hi Thomas

Did you experiment with the "image-remdering" property to see if that had
any effect?

http://www.w3.org/TR/SVG/painting.html#ImageRenderingProperty

Paul





On 3 April 2014 05:25, Smailus, Thomas O <Thomas.O.Smailus@boeing.com>wrote:

>  In creating SVG versions of our current CGM sets of bitonal and
> grayscale graphics, we discovered that the way browsers implement their
> downsampling varies widely.
>
>
>
> Specifically, IE and Firefox seem to just downsample by dropping rows and
> columns out of the raster content as they render the SVG.  Sometimes they
> do better with a PNG image, but not always (IE9 does very odd things -
> behaving differently if you directly zoom out with ctrl-'-' vs click on the
> image with the IE (+) and (-) magnifying glass first, which seem to take
> the PNG to a different behavior mode for later ctrl-'-' reduction in
> size).  Chrome does a good job and properly anti-aliases the SVG raster
> content as it reduces the size, converting the image to greyscale if it was
> bitonal by the looks of it.
>
>
>
> The short of it is that IE and Mozilla are not usable for displaying SVG
> graphics containing line art raster content, if one has to reduce the size
> of the graphics into a smaller frame, as the artwork starts to disappear
> and become unrecognizable.
>
>
>
> It may be worthwhile considering adding some guidance recommendations for
> SVG viewer implementations along the lines of it being recommended that SVG
> raster content be anti-aliased and internally stored and even rendered in a
> larger color space if necessary (eg bitonals become grayscale, etc) for the
> purposes of rendering the SVG.
>
>
>
> Thoughts?
>
>
>
> --
> Thomas Smailus
>
> The Boeing Company
>
>
>