On 08-Dec-05 Jim Rippon wrote:

Chris Green wrote:

...

What's a quick and easy tool for resizing (as in changing the default screen size) of a Jpeg file? I have some scanned images that I want to display smaller on web pages and, although gimp will do it, it does seem a bit of a sledgehammer to crack a nut.

It would be nice to be able to just say something like:-

someProgram -x 400 -y 200 <old.jpg >new.jpg

Going further, is it easy/possible to change the size of an image according to the size of the browser window being used? I use a 1600x1200 display at home so a 400x200 image will be quite small really but if anyone looks at the same page on (say) 800x600 it's going to be a bit on the large size.

Chris,

How about ImageMagick's convert program:

http://www.imagemagick.org/script/convert.php

convert old.jpg -size 400x200 new.jpg

And don't forget to have a look at all the options in "man comvert" for enhancing/smoothing/etc (you may need to look up "man ImageMagick" to get explanations of some of them).

Ted.

-------------------------------------------------------------------- E-Mail: (Ted Harding) Ted.Harding@nessie.mcc.ac.uk Fax-to-email: +44 (0)870 094 0861 Date: 08-Dec-05 Time: 12:11:05 ------------------------------ XFMail ------------------------------

On 08-Dec-05 Jim Rippon wrote:

(Ted Harding) wrote:

...

...

Chris,

How about ImageMagick's convert program:

http://www.imagemagick.org/script/convert.php

convert old.jpg -size 400x200 new.jpg

And don't forget to have a look at all the options in "man comvert" for enhancing/smoothing/etc (you may need to look up "man ImageMagick" to get explanations of some of them).

Ted.

My "man convert" page says "For more information about the convert command, point your browser to" with links to the online docs. "man ImageMagick" doesn't come up with much more in the way of an explanation of the options available.

"convert --help", however, displays all the options available along with brief descriptions, but beware this is many, many pgup's long!

Jim

Thanks for correcting my misleading message! (This was based on the memory that you look at ImageMagick for the available formats).

Ted.

-------------------------------------------------------------------- E-Mail: (Ted Harding) Ted.Harding@nessie.mcc.ac.uk Fax-to-email: +44 (0)870 094 0861 Date: 08-Dec-05 Time: 12:45:35 ------------------------------ XFMail ------------------------------

The message 439954E7.9010806@quarella.co.uk from Mark Rogers mark@quarella.co.uk contains these words:

Chris Green wrote:

...

What's a quick and easy tool for resizing (as in changing the default screen size) of a Jpeg file?

As with others here I was going to suggest imageMagick, but since they have I won't.

Instead I have a related question: Is there a way with imageMagick (or something else, for that matter, but commandline based) to shoehorn an image into a fixed size and shape, using a specified background colour where the height:width ratio of the image differs from the desired destination size?

Yes.

Eg: I have a 300x300 box to put a 400x600 image into. It would need reducing to 200x300 (so it fits the 300x300), then centred over (say) a black 300x300 rectangle to create the final image. Ideally the background colour, and alignment over the background, would be optional, but black and centred would normally be fine.

Yes.

Whenever I've used convert I've been unable to achieve this (I get the 200x300 bit easily, but that's where I get stuck). Given the myriad of options I've never been convinced the option I want isn't lurking there somewhere.

You can do it quite easily with html...

Mark Rogers wrote:

Eg: I have a 300x300 box to put a 400x600 image into. It would need reducing to 200x300 (so it fits the 300x300), then centred over (say) a black 300x300 rectangle to create the final image. Ideally the background colour, and alignment over the background, would be optional, but black and centred would normally be fine. Whenever I've used convert I've been unable to achieve this (I get the 200x300 bit easily, but that's where I get stuck). Given the myriad of options I've never been convinced the option I want isn't lurking there somewhere.

I've been lurking for a while (so by way of introduction - "hi all"). I thought I'd pipe up as this is a subject dear to my heart - I am a bit of a photo-obsessive and have over 11,000 photos on my website - most of which have been processed via Perl scripts using ImageMagick.

Here's a Perl example of implementing a composite of two images - your background (created on-the-fly) and your thumbnail:

########################################################## #!/usr/bin/perl #

use Image::Magick;

# create background...

$image = Image::Magick->new; $image->Set( size=>'300x200' ); $image->ReadImage( 'xc:black' );

# read image to add on top...

$image2 = Image::Magick->new; open ( IMAGE, 'myImageToAdd.jpg' ); $image2->Read( file=>*IMAGE );

$width = $image2->Get('width'); $height = $image2->Get('height');

if ( $width > $height ) {

# landscape print "landscape... "; $newwidth = 300; $ratio = $height / $width; $newheight = int( $mainsize * $ratio ); } else {

# portrait print "portrait... "; $newheight = 200; $ratio = $width / $height; $newwidth = int( $mainsize * $ratio ); }

$image2->Resize( width=>$newwidth, height=>$newheight, filter=>'Hamming' );

$image->Composite( image=>$image2, compose=>'Atop' ); $image->Set( quality=>"89" ); # set output JPEG quality $image->UnsharpMask( radius=>0.6, sigma=>0.7, amount=>0.7, threshold=>0.02 ); # took me /ages/ to get this right $image->Strip(); # remove space-hogging EXIF data, etc

$image->Write( 'test.jpg' ); #######################################################

Or something like that. You can fiddle around with the position your second image ends up with attributes such as Geometry - look at http://www.imagemagick.org/script/perl-magick.php and the section on "Composite".

Of course, as another poster pointed out, you could save a bit of bandwidth by wrapping your image in a suitable background-coloured table cell, <div> or <span>. Personally, I'm a big fan of cropped (as opposed to windowed) thumbnails - even though you do occasionally chop people's heads off!

Simon