#!/usr/bin/ruby

=begin
Purpose: Resizes image using RMagick to fit WxH while keeping aspect
         and stripping all EXIF crap
Author: Wejn (wejn(at)box(.)cz)
License: public-domain
Requires: Ruby >= 1.8, rubygems, RMagick (mine: 1.9.0)
TS: 20050806220000
=end

require 'rubygems'
require_gem 'rmagick'

if ARGV.size != 4
	$stderr.puts "#$0 src dst w h"
	exit 1
end

h,w = nil, nil
begin
	w = Integer(ARGV[2])
	h = Integer(ARGV[3])
rescue
	$stderr.puts "Error: w and h must be numbers!"
	exit 1
end

unless FileTest.exist?(ARGV[0])
	$stderr.puts "Error: src must exist!"
	exit 1
end

begin
	# load up
	i = Magick::ImageList.new(ARGV[0])
	puts "Image is: #{i.columns} x #{i.rows}" if $DEBUG
	puts "I want: #{w} x #{h}" if $DEBUG

	# compute new size
	r = [i.columns / w.to_f, i.rows / h.to_f].max
	nw = (i.columns / r).round
	nh = (i.rows / r).round

	puts "New size will be: #{nw} x #{nh}" if $DEBUG

	#scale it
	i2 = i.scale(nw, nh)

	# remove EXIF
	i2.profile!('*', nil)

	# write out
	i2.write(ARGV[1])
	#File.open(ARGV[1], 'w').write(i2.to_blob) # also possible
rescue
	$stderr.puts "Resize failed: #$!"
	exit 1
end
exit 0