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  sherdim 14 years ago

  This solution supposes initial keeping of the uploaded BIG image. I am not a specialist in the webserver memory utilization, but a solution with validator RESIZE, which called on any upload to the given field is more straightforward IMHO. Such solution was published in the web2py group about a year ago. It utilizes PIL also and cStringIO as a temporal buffer. The same approach was for automarking images with the site logo. Place a module with validator in module folder. ================ __all__ = [ 'RESIZE', ] class RESIZE(object): """ Resize image such as thumbnail """ def __init__(self,nx=160,ny=80,error_message='image resize error'): (self.nx,self.ny,self.error_message)=(nx,ny,error_message) def __call__(self,value): if isinstance(value, str) and len(value)==0: return (value,None) from PIL import Image import cStringIO try: #load im=Image.open(value.file) #resize im.thumbnail((self.nx,self.ny),Image.ANTIALIAS) #by hand s=cStringIO.StringIO() im.save(s,'JPEG',quality=86) s.seek(0) value.file=s except: return (value,self.error_message) else: return (value,None) =========== Vale!
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  villas 14 years ago

  The validator is good for transforming a field, but at the end you just have one image/field. In the case of this slice I wanted to automatically create a thumbnail from an upload which would result in having two files/fields. I think the use case is therefore different. However, it is still good to know this RESIZE validator. Thanks.
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  rppowell 14 years ago

  just wanted to add that the thumbnail image name matters (at least in the current version of web2py). I ended up with this code:

  
  def makeThumbnail(img_name,size=(150,150)):
      try:    
          import os
          from PIL import Image
      except: 
          return
      im=Image.open(request.folder + 'uploads/' + img_name)
      im.thumbnail(size,Image.ANTIALIAS)
      root,ext = os.path.splitext(img_name)
      thumbName='%s_thumb%s' %(root, ext)
      im.save(request.folder + 'uploads/' + thumbName)
      return thumbName
  
  def add():
      form = SQLFORM(db.Item)
      if form.accepts(request.vars, session):
          response.flash = "Item Added"
          row = db(db.Item.id==form.vars.id).select()[0]
          img_name=row.image
          thumb = makeThumbnail(img_name)
          if thumb: row.update_record(image_thumb=thumb)
      elif form.errors:
          response.flash = "Form has errors"
      return dict(form=form)
  

  Does the thumbnail really need a UUID that is not related to the original image?
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  rppowell 14 years ago

  I guess I should put back in the original error checking!
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  simpel 14 years ago

  You can do also:

  
  
  class RESIZE(object): 
      def __init__(self,nx=160,ny=80,error_message='niepoprawny plik'): 
          (self.nx,self.ny,self.error_message)=(nx,ny,error_message) 
      def __call__(self,value):
          if isinstance(value, str) and len(value)==0: 
              return (value,None) 
          from PIL import Image 
          import cStringIO 
          try: 
              img = Image.open(value.file) 
              img.thumbnail((self.nx,self.ny), Image.ANTIALIAS) 
              s = cStringIO.StringIO() 
              img.save(s, 'JPEG', quality=100) 
              s.seek(0) 
              value.file = s 
          except: 
              return (value, self.error_message) 
          else: 
              return (value, None)
              
  def THUMB(image, nx=120, ny=120):
      from PIL import Image 
      import os  
      img = Image.open(request.folder + 'uploads/' + image)
      img.thumbnail((nx,ny), Image.ANTIALIAS) 
      root,ext = os.path.splitext(image)
      thumb='%s_thumb%s' %(root, ext)
      img.save(request.folder + 'uploads/' + thumb)
      return thumb
  
  
  db.define_table('gallery',
      Field('image', 'upload', required=True, notnull=True, requires=[IS_IMAGE(), RESIZE(650, 650)]),
      Field('image_thumb', 'upload', compute=lambda r: THUMB(r['image'])))
  
  
  

  Why can't I edit my own comment? Can somebody delete my first comment? Thanks