how to convert Blob to Image?

[Ben Chang]

I can save uploaded pictures into BlobProperty in datastore by those functions:

raw_img = images.Image(pic)
raw_img.resize(width=320, height=240)
raw_img.im_feeling_lucky()

mydb.pic = raw_img.execute_transforms(output_encoding=images.PNG)
mydb.put()



Is there anyway to convert BlobProperty to Image?
Because I want to resize the picture before export to user for reduce  bandwidth.

[macarthy]

Have a look here
http://code.google.com/appengine/articles/images.html

[Ben Chang]

Tks, but I'm not just want to export the Blob data.

 

I hope I can process the Blob data to Image, and resize the image to reduse file size.

 

 

 

Perhaps your meaning is useing: urlfetch.Fetch(picture_url).content ??

 

I'll try this after weekend.

 

 

 

2008/6/20, macarthy <justin.m...@gmail.com>:

[Ben Chang]

Yes, it works!!

 

First at all, I have a class "GetPic" to get original image from datastore:

 

class GetPic(webapp.RequestHandler):
    def get(self, pic_id):
        pic = WCPicture.gql("where id = :1", int(pic_id)).get()
        if pic:
            self.response.headers['Content-Type'] = 'image/png'
            self.response.out.write(pic.pic)

 

 

Then I use "urlfetch.Fetch" int another class "GetPic2" to get the data in image type, and I can resize it now:

class GetPic2(webapp.RequestHandler):
    def get(self, pic_id):
        pic = WCPicture.gql("where id = :1", int(pic_id)).get()
        if pic:
            w = self.request.get("w")
            h = self.request.get("h")

            raw_img = images.Image(urlfetch.Fetch("/WebcamCapture/getPic/" + pic_id).content)
            if w<>"" and h<>"":
                raw_img.resize(width=int(w), height=int(h))
            raw_img.im_feeling_lucky()

            self.response.headers['Content-Type'] = 'image/png'
            self.response.out.write(raw_img.execute_transforms(output_encoding=images.PNG))

This might be increase server CPU process, but can hopefully reduce the bandwidth.

 

 

 

 

2008/6/20, Ben Chang <ben.rb...@gmail.com>:

[Ross Ridge]

Ben Chang wrote:
> Then I use "urlfetch.Fetch" int another class "GetPic2" to get the data in
> image type, and I can resize it now:

Umm... why not just do it in one request:

class GetPic2(webapp.RequestHandler):
def get(self, pic_id):
pic = WCPicture.gql("where id = :1", int(pic_id)).get()
if pic:
w = self.request.get("w")
h = self.request.get("h")

raw_img = images.Image(pic.pic)
if w!="" and h!="":

raw_img.resize(width=int(w), height=int(h))
raw_img.im_feeling_lucky()

self.response.headers['Content-Type'] = 'image/png'

self.response.out.write(raw_img.execute_transforms(output_encoding=images.PNG))

Ross Ridge

[Ben Chang]

Wow... you are right!!

 

Perhaps I did some wrong process which made me failed.

 

Anyway, thank you again.

 

 

2008/6/21, Ross Ridge <rri...@csclub.uwaterloo.ca>:

[Sharp-Developer.Net]

Hey Justyin, Ben, do you know by any chance how to upload images/files
to AppEngine using <form method="post" enctype="multipart/form-
data"> ?

I'm trying to use build-in Django 0.96 shipped with Google AppEngine
and got strugled with this :(

Here is a question with details I asked:
http://groups.google.com/group/google-appengine/browse_thread/thread/c0ca9ec08c022c61/157b6b5a9fb5235e#157b6b5a9fb5235e
--
Alexander Trakhimenok
http://sharp-developer.net/

On Jun 20, 10:01 am, macarthy <justin.maccar...@gmail.com> wrote:
> Have a look herehttp://code.google.com/appengine/articles/images.html

> > bandwidth.- Hide quoted text -
>
> - Show quoted text -