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Improved Export Functionality

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As it currently stands an export of an average chart causes the user's browser to send 180-300kb of text over the stream, which makes image generation quite flow for people with weak uplink.

 

 

 

Could you consider implementing LZW (optionally, based on a parameter) compression of the data, which substantially reduces the time needed to generate a JPEG image. For example your sample chart at http://www.fusioncharts.com/GalleryChart.asp?id=1 requires the client to send 190kb of text. LZW compression lowers that number to mere 31kb, making the export that much more practical.

 

 

 

The LZW compression is already implemented in ActionScript (http://www.razorberry.com/blog/content/LZW.as) and would be trivial to add on top of the existing code. Could you please consider implementing this functionality for the next version, we'd be happy to help test this functionality and revise the PHP rendering script to accommodate the change, not to mention provide a substantially faster PHP image rendering code.

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Hi,

 

 

 

Thanks for your suggestion.

 

 

 

We had prototyped with LZW compression too. However, since Flash 8 doesn't support byte data type natively, we had to send bytes as chr(byte's decimal value) characters, which tend to be UTF-8 characters after the initial ASCII 256 characters. Now, at server side, this was getting platform specific, as PHP and ASP.NET didn't convert it back to the original format.

 

 

 

As such, we had to resort to RLE encoding, which does provide a lot of compression (from 2MB of data to 300KB), is more processor efficient than LZW (at least in case of Flash), but the compression factor is higher.

 

 

 

In Flash 9, this can be easily done, as ByteArray is supported and GZip compression is natively supported. As such, we expect to provide a better way to do this in FusionCharts v4.

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