Server Imaging Sample
This demo application performs additional image processing on the server after images are uploaded. It rotates uploaded images if necessary and adds a border to them, like this one:
Figure 1. Sample image.
Unlike other demo applications, this one uses Image Uploader merely for the upload and thumbnail rotation, if needed. No other image processing is carried out on the client side.
Features
The application highlights the following features:
- Server image processing.
- File filtering by extension.
Client-Side Code
The sample presumes that you upload an unchanged original file and a single thumbnail.
Note that the source file is not modified even if the user has rotated it (by
design). Instead, the angle is uploaded as an Angle_N field,
where N is the number of the corresponding file. The value of this field is
used by the server script for performing rotation. The thumbnail is sent already rotated though.
File Filtering
This application also demonstrates how to allow users to upload images only of certain types. Files of other types simply will not be shown while browsing. Extensions of the allowed files are listed as a value of the FileMask property. For more information, see the Restricting Files by Extensions and Types topic.
Server-Side Code
On every platform the upload script simply iterates through all the files, rotates them, and, if necessary, draws a border around each of them. Some platforms require installation of additional libraries or components to enable image processing.
Imaging Components
The following components are used in this sample for different platforms:
| Platform | Used components |
|---|---|
| ASP.NET | Built-in classes from the System.Drawing namespace |
| ASP | Aurigma Graphics Mill ActiveX component. |
| PHP | GD2 extension |
| JSP | Built-in classes from the java.awt package |
| Perl | ImageMagick module |
| Python | Python Imaging Library (PIL) |
| Ruby | RMagick extension |
This sample is not implemented for the ColdFusion platform.