gem 'image_resizer'

image = ImageResizer::TempObject.new(File.new(path_to_image_file))
processor = ImageResizer::Processor.new

# resize to fit the specified width, maintaining the original ratio
tempfile = processor.resize(temp_object, :width => 320)

# resize to fit the specified height, maintaining the original ratio
tempfile = processor.resize(temp_object, :height => 240)

# resize to the specified dimensions, cropping around the center to avoid stretching
tempfile = processor.resize(temp_object, :width => 320, :height => 240)

# crop the original image to a frame and resize the result
upper_left = [0.25, 0.15] # 25% from the left, 15% from the top 
lower_right = [0.75, 0.95] # 75% from the left, 95% from the top
width = 320
tempfile = processor.crop_to_frame_and_resize(temp_object,
                                  :upper_left => upper_left,
                                  :lower_right => lower_right,
                                  :width => width
                                  )

# crop the original image around a point and resize the result
point = [0.8, 0.3] # 80% from the left, 30% from the top
width = 320
height = 400
tempfile = processor.resize_and_crop_around_point(temp_object,
                                  :point => point,
                                  :width => width,
                                  :height => height
                                  )
File.open(path_to_output_file, 'wb') { |f| f.write(File.read(tempfile)) }


# generate a .ico file with 16, 32, 64, 128, and 256 pixel square sizes
tempfile = processor.generate_icon(temp_object)
File.open(path_to_output_file, 'wb') { |f| f.write(File.read(tempfile)) }