Class: Fleximage::Operator::Resize

Inherits:
Base
  • Object
show all
Defined in:
lib/fleximage/operator/resize.rb

Overview

Resize this image, constraining proportions. Options allow cropping, stretching, upsampling and padding.

image.resize(size, options = {})

size is size of the output image after the resize operation. Accepts either '123x456' format or [123, 456] format.

Use the following keys in the options hash:

  • crop: pass true to this option to make the ouput image exactly the same dimensions as size. The default behaviour will resize the image without cropping any part meaning the image will be no bigger than the size. When :crop is true the final image is resized to fit as much as possible in the frame, and then crops it to make it exactly the dimensions declared by the size argument.

  • upsample: By default the image will never display larger than its original dimensions, no matter how large the size argument is. Pass true to use this option to allow upsampling, disabling the default behaviour.

  • padding: This option will pad the space around your image with a solid color to make it exactly the requested size. Pass true, for the default of white, or give it a text or pixel color like "red" or color(255, 127, 0). This is like the opposite of the crop option. Instead of trimming the image to make it exactly the requested size, it will make sure the entire image is visible, but adds space around the edges to make it the right dimensions.

  • stretch: Set this option to true and the image will not preserve its aspect ratio. The final image will stretch to fit the requested size. The resulting image is exactly the size you ask for.

Example:

@photo.operate do |image|
  image.resize '200x200', :crop => true
end

Instance Method Summary collapse

Methods inherited from Base

#color, color, #execute, #initialize, #scale, #scale_and_crop, size_to_xy, #size_to_xy, #stretch, #symbol_to_blending_mode, #symbol_to_gravity

Constructor Details

This class inherits a constructor from Fleximage::Operator::Base

Instance Method Details

#operate(size, options = {}) ⇒ Object 



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# File 'lib/fleximage/operator/resize.rb', line 39

def operate(size, options = {})
  options = options.symbolize_keys
  
  # Find dimensions
  x, y = size_to_xy(size)

  # prevent upscaling unless :usample param exists.
  unless options[:upsample]
    x = @image.columns if x > @image.columns
    y = @image.rows    if y > @image.rows
  end

  # Perform image resize
  case
  when options[:crop] && !options[:crop].is_a?(Hash) && @image.respond_to?(:crop_resized!)
    # perform resize and crop
    scale_and_crop([x, y])

  when options[:stretch]
    # stretch the image, ignoring aspect ratio
    stretch([x, y])

  else
    # perform the resize without crop
    scale([x, y])

  end

  # apply padding if necesary
  if padding_color = options[:padding]
    # get color
    padding_color = 'white' if padding_color == true

    # get original x and y.  This makes it play nice if the requested size is larger 
    # than the image and upsampling is not allowed.
    x, y = size_to_xy(size)

    # get proper border sizes
    x_border = [0, (x - @image.columns + 1) / 2].max
    y_border = [0, (y - @image.rows    + 1) / 2].max

    # apply padding
    @image.border!(x_border, y_border, padding_color)

    # crop to remove possible extra pixel
    @image.crop!(0, 0, x, y, true)
  end
  
  return @image
end