Legacy ImageMagick Discussions Archive

Hi,

I want to resize all png files in directory to match heigth 190px, but some images less than 190 and some bigger. So I want to have if statement in bash script like this

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for f in *.*
do 
	h=`identify -format %h $f` | if [ "$h" -gt 190 ]; then convert $f -strip -thumbnail x190 test/$f; fi ;
	convert $f -strip -gravity center -extent x190 -transparent white test/$f;
done

So images that less than 190px height will be enlarged to 190px without increasing in width.
Images that bigger than 190px height will be resized to 190px.

But it seems that I have some problem here [ "$h" -gt 190 ]

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$ sh images.sh
images.sh: line 38: [: : integer expression expected
images.sh: line 38: [: : integer expression expected
images.sh: line 38: [: : integer expression expected
`1.png' -> `../../../public/img/1.png'
`2.png' -> `../../../public/img/2.png'
`3.png' -> `../../../public/img/3.png'

if [ "$h" -gt 190 ]

Remove the quotes around $h, since they are integers and -gt expects number not strings.

so use

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if [ $h -gt 190 ]

Alternately, you can avoid the if tests, if you compute the percent ratio of 100*190/imageheight = pct, so that you use

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-thumbnail 100x$pct%!

So images that less than 190px height will be enlarged to 190px without increasing in width.

Perhaps I misunderstood. If you do what I said above with the resize, then you will distort the look of the images, if you force the width not to change, and resize only the height. Is that what you really want?

Or do you want to resize both dimensions to fit the 190 height and preserve aspect ration, but then crop or pad to the original width? You can do that by simply getting the image width before processing and then resize and extend.

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width=`convert image -format "%w" info:`
convert image -thumbnail x190 -gravity center -background none -extent ${width}x190 result

I use this code

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if [ "$h" -gt 190 ]

because I checked that when using this

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if [ $h -gt 190 ]

I got following error

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images.sh: line 38: [: -gt: unary operator expected

I don't know why.

Anyway thanks for your help. I found good solution with you. The code below do the job.
A little bit more explanation for you to better understand my target. I have folder with png files with transparency. To have good looking web page I need all of them height 190px.
So if initial height less than 190px I just extent height adding transparent pixels and not distorting initial picture.
And if initial height greater than 190px I resize picture down to 190px height keeping aspect ratio. hope you understand me now.

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for f in *.*
do 
	w=`convert $f -format "%w" info:`
	h=`convert $f -format "%h" info:`
		if [ $h -gt 190 ]; 
			then convert $f -strip -transparent white -thumbnail x190 output/$f; 
			else convert $f -strip -gravity center -transparent white -extent ${w}x190 output/$f; 
		fi
done

You should not need the conditional. Use -thumbnail x190>. The > means if larger than 190.

Try

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convert $f -strip -thumbnail x190> \
-gravity center -background none -extent ${w}x190 \
output/$f

see
http://www.imagemagick.org/script/comma ... p#geometry

This is likely your problem:

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h=`identify -format %h $f` | if [ "$h" -gt 190 ] ...

There is nothing specified to pipe. Try separating it into two statements and using the variable as integer number not character.

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h=`identify -format "%h" $f`
if [ $h -gt 190 ] ...

But this should not be needed, if you use my method above with the -thumbnail x190>

unfortunately this

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convert $f -strip -transparent white -thumbnail x190> -gravity center -extent ${w}x190 output/$f

gives me an error

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convert.exe: unable to open image `center': No such file or directory @ error/blob.c/OpenBlob/2709.

I think this because ">" assumed like redirection operator

You should remove the -transparent white unless there is white in your input image that you need to replace with transparent. The -background none does the extent with a transparent background.

Do it as exactly the following

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convert $f -strip -thumbnail "x190>" -gravity center -background none -extent ${w}x190 output/$f

or

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convert $f -strip -thumbnail x190\> -gravity center -background none -extent ${w}x190 output/$f

Do either work?

What version of IM are you using and on what platform?

both works. Thank you.

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$ uname -a
MINGW32_NT-6.1 WIN-SV4R9NF6R3V 1.0.12(0.46/3/2) 2012-07-05 14:56 i686 unknown

OK. Good. But out of curiosity, what version of IM.

Version: ImageMagick 6.8.9-9 Q16 x86 2014-10-19

it is integrated in openserver package for local development

could you also help me with this issue. It is very similar with error above

If I do this, it is OK.

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mogrify -path ../out1 -filter Triangle -define filter:support=2 -thumbnail 640 \
-unsharp 0.25x0.08+8.3+0.045 -dither None -posterize 136 -quality 82 \
-define jpeg:fancy-upsampling=off -define png:compression-filter=5 \
-define png:compression-level=9 -define png:compression-strategy=1 \
-define png:exclude-chunk=all -interlace none -colorspace sRGB *

but if I do this

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smartresize() {
   mogrify -path $3 -filter Triangle -define filter:support=2 -thumbnail $2 \
   -unsharp 0.25x0.08+8.3+0.045 -dither None -posterize 136 -quality 82 \
   -define jpeg:fancy-upsampling=off -define png:compression-filter=5 \
   -define png:compression-level=9 -define png:compression-strategy=1 \
   -strip -define png:exclude-chunk=all -interlace none -colorspace sRGB $1
}

smartresize resources/img/* 640 out/

then I have error

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$ sh images.sh
mogrify.exe: invalid argument for option `resources/img/avangard.png': -thumbnail @ error/mogrify.c/MogrifyImageCommand/6200.

I tried

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smartresize resources/img/* 640 out/
smartresize resources/img/* "640" out/
smartresize resources/img/* '640' out/

but always error

This isn't a scripting foum, and I'm no expert on bash, but what arguments is smartresize() receiving? Put an echo at the start to see the first 3 arguments.

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