large byte size for charts

[Marcus Bjorke]

Hi. Does anybody know how to compress images produced by JFreeChart?

From my point of view the graphs produced by JFreeChart are very large. Is there any way to compress them more. I am using png and the image is about 28 kb. I can easily reduce that size with any image-editor down to about 10 kb without loosing visible quality.

Thanks,
Marcus

[David Gilbert]

Hi Marcus,

I use a free (GNU LGPL) class called PngEncoder to encode the PNG files. It was written by J. David Eisenberg.

I notice in that class there is a constructor that allows you to specify the compression level:

public PngEncoder( Image image, boolean encodeAlpha, int whichFilter,
int compLevel)

The default seems to be zero, you could try altering that to see what effect it has.

Regards,

DG.