Re: Image compression

Posted by Yong Zhang-2-3 on Dec 23, 2005; 4:18am
URL: http://imagej.273.s1.nabble.com/Image-compression-tp3704130p3704133.html

Hi, John,

If the image compression is "lossless", then the measurements will not be
affected since no information is lost during the compression. The lossless
compression is a good way to store/transfer large dataset without any loss
of the useful information. But you have to make sure that the compression
is really "lossless" when using any software, because one format can be
either lossless or lossy. For example, JPEG format can be lossless or
lossy. So you must select lossless mode when saving your original image
into another format. If your software does not provide lossless/lossy
selection when saving images, then you'd better switch to another software
which has the selection.

I hope it helps.

Best,


Yong Zhang



John T. Sharp said:

> I am starting a project measuring features of hand and foot x-rays on 400
> to 600 sets ( 4 each set) so it is a rather large project. I'm estimating
> 250-350 hours.  There is some controversy among colleagues who we also be
> participating as to wheter measurements are likely to be affected by
> transmitting the images in compressed TIFF format.  I will be using the
> Microsoft Photo Editor to decompress them and then making the measurements
> with an ImageJ plugin.
>
> Would anyone with the engineering/math/computer science background
> sufficiently broad to know whether this "lossless"
> compression-decompression system will influence the measurements comment
> on this problem.
>
> John T. Sharp
>