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Upload Image and make a Thumbnail
Recipe by David Harrison (villas) on 2010-02-21 in Controller

This is a method I found to upload an image (into the uploads folder) and then create the thumbnail in the same directory. One good point is that Web2py allocates the filenames so everything can have authorization etc. It requires the Python Image Library installed.

Model:

db.define_table('uploads',
    Field('name','string'),
    Field('mainfile','upload'),
    Field('thumb','upload',writable=False,readable=False),
    )

Controller:

def makeThumbnail(dbtable,ImageID,size=(150,150)):
    try:    
        thisImage=db(dbtable.id==ImageID).select()[0]
        import os, uuid
        from PIL import Image
    except: return
    im=Image.open(request.folder + 'uploads/' + thisImage.mainfile)
    im.thumbnail(size,Image.ANTIALIAS)
    thumbName='uploads.thumb.%s.jpg' % (uuid.uuid4())
    im.save(request.folder + 'uploads/' + thumbName,'jpeg')
    thisImage.update_record(thumb=thumbName)
    return 

def uploadimage():
    dbtable = db.uploads          #uploads table name
    if len(request.args):
        records = db(dbtable.id==request.args[0]).select()
    if len(request.args) and len(records):
        form = SQLFORM(dbtable, records[0], deletable=True)
    else:
        form = SQLFORM(dbtable)
    if form.accepts(request.vars, session): 
        response.flash = 'form accepted'
        makeThumbnail(dbtable,form.vars.id,(175,175))
    elif form.errors:
        response.flash = 'form has errors'
    ## Quick list just to demonstrate...
    list = crud.select(dbtable)
    return dict(form=form,list=list)

(I am grateful to Lukasz (aka ls1) for his kind assistance).

Image Thumbnails Upload

Related slices

Comments (11)

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  • 0
    gheither 10 years ago

    This slice used to work for me about a year ago, now it's not after I upgraded my web2py.  Can anyone get this working with the latest web2py build?

    It creates the thumbnail successfully and stores it in the uploads folder, but when you try to retrieve the thumbnail through the URL bar or the DB admin screen you get a ticket.

    <type 'exceptions.TypeError'> Can't retrieve uploads.thumb.16e0d9fd-bc66-4b36-9c75-03aaea1d8603.PNG

    Please help!


  • 0
    eanappi 10 years ago
    I did what I explained and it worked perfect. But when uploading in Amazon EC2 does not work.
     
    There are dependencies to use this module?
    replies (1)
    • villas 10 years ago

      Of course, as noted you need PIL to be installed. Check filesystem permissions of the folder that your python/webserver can write files. BTW I like the code by simpel in the comments.


  • 0
    write2ariya 11 years ago

    Dear David

     

    This is very useful. I use you code in my project. Thank you for your contribution & sharing.

    (just wanna thanks, I will payback web2py community someway)

    Ariya


  • 0
    simpel 13 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

  • 0
    mrfreeze 13 years ago
    I deleted it and will add comment editing. I thought previewing would be enough.
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