I've played with the
EPS file you linked in the comment above. As you said, after conversion the white grid is showing up in the
PDF and even in the
PNG after using
convert -density 300x300 branin.eps branin.png
The only thing I know to get rid of the grid is to convert to a very high resolution
PNG and then scale the
PNG down. The white grid gets averaged into the surrounding colors during the scaling. These commands might take a few minutes depending on your processor speed. Depending on your operating system, you might need to replace
%% in the second command.
convert -density 2400x2400 branin.eps braninTemp.png
convert -scale 10% braninTemp.png branin.png
Of course the downside of this process is that you are left with a raster image instead of a vector image. Here's a view of the resulting
Another option that you apparently are aware of is to take a screen shot of the
EPS file in whatever viewer you used to generate the image in your question.