Create BLOB's Image Thumbnail

[Tec-Nico]

After searching through the forums it seems there is no topic discussing how to create a thumbnail of a picture you store into a BLOB Field in Access...

Is there a way to create a thumbnail of a picture stored in a MSSQL (or Access' OLE Object) BLOB?

I was wondering if when storing the picture into the DB you can manipulate the data to make a thumbnail (using an algorithm to create it, of course) and store it into a different field or if when retrieving the data from the field to manipulate the stream and turn it into a thumbnail before displaying it?

Thanks in advance for your replies

[si_the_geek]

The reason for no threads about it is that creating thumbnails should not be done on the database side - it should be done with the image itself.

The reason for this is that there are many picture file formats, and the SQL commands to work with it would be horrendous, and probably very inefficient too.


If the thumbnails are likely to be used relatively regularly (and more than the 'full' image), then storing them in the database is a good idea, as long as you can cope with the size of the extra blob field (Access may have issues).


Depending on how you are uploading the original pictures, it is likely to be best to create the thumbnail at the same time. Otherwise you will need to extract the image from the database in order to create the thumbnail.

[Tec-Nico]

Thanks for your answer, si. In case I would like to create the thumbnail when uploading the original picture, how would I do that?

I know that doing it with SQL would be horrible, it didn't deserve any thought from my part.

The thumbnails are going to be used regularly since they would be images of a product catalog. Right now I just have code to store and display the BLOB and would appreciate some advice.

[si_the_geek]

I'm not really the one to answer that, however this thread should have the answer for you:
http://vbforums.com/showthread.php?s=&threadid=237900

[Tec-Nico]

Thank you, I just went there and checked the code. It is an interesting piece of code but then I wonder if it is possible to do that in an ASP page.

Are you allowed to call API from ASP? I am not sure about that.

[si_the_geek]

I've got no idea, it's worth a try.

You'd have to ask in the ASP forum to get an accurate answer.