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Question

resize photo files?

Aug 17, 2011 1:23AM PDT

how can you reduce the size of typical photo files, such as tif, gif, jpeg, bmt, without compromising the photos?

Discussion is locked

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Answer
Great question.
Aug 17, 2011 1:48AM PDT

But so far it has not been possible. All reductions so far do so by two methods. Compressing of the data such as ZIPping or by lossy compression.

The answer is for today, you can't.

Maybe someday there will be a truly loss less compression that will make a dent more than zipping but not yet.
Bob

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resize photo files?
Aug 17, 2011 2:52AM PDT

the wide variation in file sizes is a source of confusion for me. why are my files 1MB when others that are forwarded to me are 112kb, for what appear to be same file sizes and types? do certain applications create larger files than others?
thanks, dave

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That's not the topic?
Aug 17, 2011 3:11AM PDT

But the shortest answer to your question is yes.

You should post this in the CNET Digital Camera Forum if you want to go beyond what the How To forum tries to be. That is, so far the How To appears to be not about discussions but a question and an answer.

Back to your question. There is no current method beyond zipping that is lossless. However most people can't tell the difference between a JPEG compressed at the 51% or the 75% quality levels without pulling up the images side by side and zooming in.

But let's get out of the How To Forum for that discussion.
Bob

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Try Irfanview
Aug 17, 2011 3:12AM PDT

It is a free image editor utility that allows the resizing of images;
http://www.irfanview.com/

I would work on a copy of the photos you have and not the original, then you can test and compare.

Why do file sizes differ? It's a big question, but in general different file types are different quality images and the better the quality the larger the file.

For example, a photo in JPEG format is a smaller file size than the same dimension photo in BMP format.

Mark

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photo files
Aug 17, 2011 3:40AM PDT

thanks for the info Mark!
Dave