* edoc [04-11-04 17:01]:

Patrick Shanahan wrote:

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* edoc [04-11-04 15:18]:

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I need to reduce the density of a bunch of jpg photos used for a Web site. (Host is complaining that I am already over the limit and I've only just started!).

man ImageMagick, particularly convert.

ImageMagick gets it done elegantly!

mogrify -scale %50 filename.jpg

WARNING! One does need to stash an original of the files to be shrunk, or make a copy of them in a new folder especially for shrinkage, as the default for mogrify is to overwrite the original.

note: posting reformatted, top-posted. Not if used as the man pages suggests: convert [ options ... ] input_file output_file -- Patrick Shanahan Registered Linux User #207535 http://wahoo.no-ip.org @ http://counter.li.org HOG # US1244711

Patrick Shanahan wrote:

* edoc [04-11-04 17:01]:

...

Patrick Shanahan wrote:

...

* edoc [04-11-04 15:18]:

...

I need to reduce the density of a bunch of jpg photos used for a Web site. (Host is complaining that I am already over the limit and I've only just started!).

man ImageMagick, particularly convert.

ImageMagick gets it done elegantly!

mogrify -scale %50 filename.jpg

WARNING! One does need to stash an original of the files to be shrunk, or make a copy of them in a new folder especially for shrinkage, as the default for mogrify is to overwrite the original.

Not if used as the man pages suggests: convert [ options ... ] input_file output_file

OK, tried that as: convert -scale %50 tubetester1.jpg tubetester1b.jpg The original size was approx. 740K the result 138K, so that means the scale-down was TO 25% of the original rather than TO 50% of the original. I saw the same result from the mogrify -scale %50 filename.jpg command. Why might that be, please? -- Thanks! doc West Central Florida Linux-Incompatible hardware is defective! USA Pres. Election 2004: http://www.rnc.org/ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

* edoc [04-11-04 18:01]:

OK, tried that as:

convert -scale %50 tubetester1.jpg tubetester1b.jpg

The original size was approx. 740K the result 138K, so that means the scale-down was TO 25% of the original rather than TO 50% of the original.

I saw the same result from the mogrify -scale %50 filename.jpg command.

Why might that be, please?

I just did a test of a jpg that is 2048x1536 as: scale 1024x768 and scale %50, results: Kaiden.jpg 1210907 2048x1536 Kaiden1.jpg 84609 1024x768 Kaiden2.jpg 84609 1024x768 84609/1210907=.0698......7% identify (ImageMagick) shows that I got exactly what I requested even though the file size is much smaller. I would have expected ~25% result. Half the height times half the width *would* result in a figure 25% of the original. Everything is relative. The jpg compression level is also a factor. Perhaps the quality/compression level of the original was greater that the result. Compression level is adjustable with the -quality parameter. -- Patrick Shanahan Registered Linux User #207535 http://wahoo.no-ip.org @ http://counter.li.org HOG # US1244711