Thursday, October 7, 2010

Grails Image Processing with the ImageTools Plugin

I recently had a requirement on my side project to add some simple image processing.  I had previously used the ImageTools plugin, but that seems to have falled into a bit of disrepair.  I had a multistep process to get this going, and I figured I'd share it.

According to the git repository, the last checkin on version 1.0.4 was way back in January 2010.  Grabbing the plugin using the standard grails install-plugin as documented on the plugin documentation page just doesn't cut it.  When attempting to use the documentation, you get a message that tells you
unable to resolve class ImageTool @ line xxx, column xxx. def imageTool = new ImageTool();
This is troubling, as that is the only class included in the plugin.  Fortunately I found this comment on a closed (???) issue on github:
So, to solve this I had to run a git clone on this source tree and then follow the instruction at the link below to create my own version of this plugin with correct package.
So it would seem that you need to grab the source, then create a plugin.  This is not as easy as you might think.  First of all, you might not have git installed.  Follow the instructions here to 'git git'.  Next, you need to grab the code.  From the command prompt in the directory you want the code, run the following command:

git clone

Now you have the code.  Even though it's a plugin, you have to tell grails it's a plugin, by running the grails create-plugin command.  Now you have a zip file that you can install in your project, using the standard grails install-plugin command.

From there you can follow the instructions.  The import statement is recognized, and we can get finally get down to actually writing the controller code:

import org.grails.plugins.imagetools.*


//the controller method we submit to
def myProfileSave = {


uploadPhoto( file, user )



def uploadPhoto( upfile, user ) {

 if(upfile.empty) {
  flash.message = 'File cannot be empty'
  redirect( action: 'myProfile' )

 def imageTool = new ImageTool()

 imageTool.load( upfile.getBytes() )

 // Crops it to a square
        //make the new squared image the image to operate on 
 // Reduces the image size
 imageTool.thumbnail( 125 )

 def fileBase = grailsApplication.config.imageLocation
 def fullPath = "${fileBase}/user/photo"
        File fullPFile = new File( fullPath )

 if ( !fullPFile.exists() ) {
 def filePath = "${fullPath}/user_${}_125.jpg"

 File toMake = new File( filePath )

 if ( !toMake.exists() ) {
 // Saves the result
 imageTool.writeResult( filePath, "JPEG" )

Once you get the plugin working, it's a breeze, as you can see!  It's a great, simple wrapper around the nasty and complicated JAI library.

Some Tips:

1) You'll probably want to increase your heap size if you are running with a default or small heap.  This requires a bit of memory.
2) Remember to specify a multi-part form.  A good explanation of this can be found in the grails documentation.
3) Profit!
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