Converting .tiff -to-> .png?

Hello there, I need to scale down a .tiff file and turn it into a .png
file. I’ve thought of several options to doing this but as a newbie I’d
appreciate if somebody could please provide some direction as to which
option to pursue:

OPTION 1: use someone else’s


I looked in core and stdlib. I found nothing. Then I searched for ‘tiff’
at rubyforge.org but also nothing.

Am I going about trying to find an appropriate gem in the correct
manner? (I can’t be the only person ever needing to this!)

OPTION 2: imagemagick


I’ve found http://www.imagemagick.org/script/index.php It does not have
a ruby interface. But I can use this tool from the command line. Lets
say I install imagemagick on windows which is also where I will run my
convert_tiff_to_png.rb script from. Lets say I’ve put imagemagick in my
system path too. Looking at the imagmagick docs:

$magick>convert -size 100x100 image.tiff image.png

So within a ruby script, how do I say “run this line as if from the
windows command prompt”?

OPTION 3: ms paint


If I open a .tiff file in paint, I simply do Edit > resize and File >
save as… and select .png

Its really easy in paint. I just have to do this a couple of thousand
times so I really need this in ruby. Is there an easy way to drive paint
from ruby?

I get the feeling imagemagick is my best/easiest option?

Thank-you, michelle

On Mon, Aug 15, 2011 at 8:20 PM, Michelle P.
[email protected] wrote:

OPTION 2: imagemagick


I’ve found http://www.imagemagick.org/script/index.php It does not have
a ruby interface. But I can use this tool from the command line. Lets
say I install imagemagick on windows which is also where I will run my
convert_tiff_to_png.rb script from. Lets say I’ve put imagemagick in my
system path too. Looking at the imagmagick docs:

Actually, there’s RMagick (and RMagick 2 for Ruby 1.9.x), which are
Ruby bindings for ImageMAgick (which will need to be installed,
obviously).

It can be a bit of a hassle to install, though:

http://rmagick.rubyforge.org/install-faq.html


Phillip G.

phgaw.posterous.com | twitter.com/phgaw | gplus.to/phgaw

A method of solution is perfect if we can forsee from the start,
and even prove, that following that method we shall attain our aim.
– Leibniz

For Windows, instaling ImageMagick + RMagick is fairly simple. Just
download this[1] and follow instructions inside. (Unfortunately, this
only works with Ruby 1.8.6.)

[1]
http://rubyforge.org/frs/download.php/64917/RMagick-2.12.0-ImageMagick-6.5.6-8-Q8.zip

But do you really need to do this in Ruby? If you just want to process
a couple hundred images once, I’d recommend IrfanView and it’s Batch
Conversion.

– Matma R.

2011/8/15 Phillip G. [email protected]:

Thanks very much Phillip and Bartosz for your replies.

(Unfortunately, this only works with Ruby 1.8.6.)

Bartosz, regarding the installation. I have to use 1.9.2. Phillip’s link
says I need to then install rmagick2 (windows) with the stated
prerequisite of “Ruby 1.8.2 and later, including Ruby 1.9…” If I just
install Ruby1.9.2-p290 from rubyinstaller.org will the requirement of
1.8.2 be satisfied or do I physically have to install 1.8.2 separately?

But do you really need to do this in Ruby?
I left a bit of information in a (lost) effort to be concise. I’m using
this script to communicate with a webapp called mingle from
thoughtworks-studios.com . The script will be called once initially for
all existing cards in mingle. And then every time there after when
we create a new card in mingle. For us a card in mingle represents a job
we have to do in our engineering workshop. Each job has a drawing
showing the machinist knows what to make. Mingle only previews .png
files but our clients gives their drawings to us in .tiff format. I need
to convert it to .png on the fly. Which is why I need this working in
ruby. The .tiff collection of drawings is every growing as are the jobs
we add. I can’t do it once off.

Oooof I feel like I’ve just had one of those conversations where I’ve
bored everyone with the detail! :slight_smile:

thanks again, michelle

Do the following blog contributions from our
https://github.com/oneclick/rubyinstaller/wiki/Tutorials page help?

http://www.waydotnet.com/blog/2010/02/rmagick-on-ruby-1-9-1-i386-mingw32-work-d/
http://phosphor-escence.blogspot.com/2010/10/install-rmagick-on-mingw-and-msys.html

Also, you might scan past messages from our google group

http://groups.google.com/group/rubyinstaller/search?group=rubyinstaller&q=rmagick

Jon

Thanks Jon, I followed the instructions on phosphor-escence.
Unfortunately I couldn’t get the rmagick gem to install(see attachment).
If anyone has any ideas I’d be real interested to hear them.

But I did get ImageMagick to install and instead (of using rmagick) I
just issue ImageMagick commands directly from my ruby code. Not as nice
but it works.

For completeness of this post here are my exact steps:

[0]
I installed ruby192 as well as the DevKit using
http://rubyinstaller.org/ on windows 7.

[1]
Installed ImageMagick-6.7.1-10-Q16-windows-dll.exe

[2]
I confirmed ImageMagick works via command prompt with:

  • % C:\ImageMagick-6.7.1-Q16\convert.exe convert.tif -resize 10% new.png

[?]
I attempted to instal the ‘rmagick’ gem with the below command. I got an
error. (see attachment) and gave up.

  • % gem install rmagick --platform=ruby –
    –with-opt-lib=C:/ImageMagick-6.7.1-Q16/lib
    –with-opt-include=C:/ImageMagick-6.7.1-Q16/include

[4]
Instead of using RMagick, I just call the ImageMagick CMD command
directly from my ruby script:-
if (system(‘C:\ImageMagick-6.7.1-Q16\convert.exe convert.tif
new.png’))
puts “yahoo! converting tif to png worked”
else
puts “oof it failed”
end

[lastly]
If I could have gotten the rmagick gem to install, this is how I would
do the same command in [4] but in nicer ruby code:
require ‘RMagick’
png = Magick::ImageList.new(“convert.tif”)
png = png.scale(300, 300)
png.write “new.png”

Cheers Michelle

2011/8/16 Michelle P. [email protected]:

Thank-you Phillip and Bartosz.

(Unfortunately, this only works with Ruby 1.8.6.)

Bartosz, regarding the installation. I have to use 1.9.2. Phillip’s link
says I need to then install rmagick2 (windows) with the stated
prerequisite of “Ruby 1.8.2 and later, including Ruby 1.9…” If I just
install Ruby1.9.2-p290 from rubyinstaller.org will the requirement of
1.8.2 be satisfied or do I physically have to install 1.8.2 separately?

My link is to a precompiled binary version of the gem, built for 1.8.6

  • RMagick2 itself should work with 1.9, if you build it properly.
    There are similar prebuilt ones for Ruby 1.8.5 and some others, but
    unfortunately none for 1.9.x, and I think building RMagick yourself on
    Windows is quite a hassle (I’ve never really tried it though - it
    didn’t work at the first time, so I stuck to 1.8.6 when I need to use
    it).

– Matma R.

unsubscribe

I have never tried to convert .tiff to .png before. I was using this
Tiff conversion tool:
http://www.yiigo.com/guides/csharp/how-to-tiff-convert.shtml
You can have a try. I hope it helps.

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