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Tricon on 09/09/07


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resize rails ruby upload rmagick


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Upload and resize with RMagick


 / Published in: Rails
 

URL: http://pastie.caboo.se/95581

Use this to upload and resize your images using RMagick. Code by nixnewbie.

  1. require 'RMagick'
  2. class Profile < ActiveRecord::Base
  3. belongs_to :user
  4.  
  5. #image = the image passed from params[:image]
  6. #file_type = the confirmed filetype from the controller
  7. #current_user = various information about the current user
  8. def self.upload(image, file_type, current_user)
  9. #set default cols and rows for our two images that will be created from the uploaded user image
  10. img_size = {:main =>{:cols => 250,:rows => 375},
  11. :thumb =>{:cols =>80, :rows =>120}
  12. }
  13. #set base directory for the users image
  14. imgDir = "#{RAILS_ROOT}/public/images/user_images"
  15. #set the base name for our userimage
  16. userImg = " #{current_user.login}-#{current_user.id}"
  17. #loop through the image dir and delete any old user images
  18. Dir.foreach(imgDir){|file|
  19. if file.to_s.include?(userImg)
  20. File.unlink("#{imgDir}/#{file}")
  21. end
  22. }
  23. #read the image from the string
  24. imgs = Magick::Image.from_blob(image.read)
  25. #change the geometry of the image to suit our predefined size
  26. main_image = imgs.first.change_geometry!("#{img_size[:main][:cols]}x#{img_size[:main][:rows]}") { |cols, rows, img|
  27. #if the cols or rows are smaller then our predefined sizes we build a white background and center the image in it
  28. if cols < img_size[:main][:cols] || rows < img_size[:main][:rows]
  29. #resize our image
  30. img.resize!(cols, rows)
  31. #build the white background
  32. bg = Magick::Image.new(img_size[:main][:cols],img_size[:main][:rows]){self.background_color = "white"}
  33. #center the image on our new white background
  34. bg.composite(img, Magick::CenterGravity, Magick::OverCompositeOp)
  35.  
  36. else
  37. #in the unlikely event that the new geometry cols and rows match our predefined size we will not set a white bg
  38. img.resize!(cols, rows)
  39. end
  40. }
  41. main_image.write "#{imgDir}/#{userImg}.#{file_type}"
  42.  
  43. thumb = imgs.first.change_geometry!("#{img_size[:thumb][:cols]}x#{img_size[:thumb][:rows]}") { |cols, rows, img|
  44. if cols < img_size[:thumb][:cols] || rows < img_size[:thumb][:rows]
  45. img.resize!(cols, rows)
  46. bg = Magick::Image.new(img_size[:thumb][:cols],img_size[:thumb][:rows]){self.background_color = "white"}
  47. bg.composite(img, Magick::CenterGravity, Magick::OverCompositeOp)
  48.  
  49. else
  50. img.resize!(cols, rows)
  51. end
  52. }
  53. thumb.write "#{imgDir}/#{userImg}-thumb.#{file_type}"
  54. if FileTest.exist?("#{imgDir}/#{userImg}.#{file_type}")
  55. return "The file was written and its name is #{userImg}.#{file_type}"
  56. else
  57. return false
  58. end
  59. end
  60. end

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