Image resize in Grails

Question

I am developing a Web Album using Grails and for image processing, I am using grails-image-tools plugin. I need a functionality to resize the images if the uploaded images size is too big (for eg: more than 600 * 840 ) . In this case I need to resize this image to 600 * 840). What is the most efficient way to do this? Thanks a lot.

Answer 1

import java.awt.Image as AWTImage 
import java.awt.image.BufferedImage      
import javax.swing.ImageIcon 
import javax.imageio.ImageIO as IIO  
import java.awt.Graphics2D


static resize = { bytes, out, maxW, maxH -> 
    AWTImage ai = new ImageIcon(bytes).image 
    int width = ai.getWidth( null ) 
    int height = ai.getHeight( null )

    def limits = 300..2000 
    assert limits.contains( width ) && limits.contains( height ) : 'Picture is either too small or too big!'

    float aspectRatio = width / height float requiredAspectRatio = maxW / maxH

    int dstW = 0 
    int dstH = 0 
    if (requiredAspectRatio < aspectRatio) { 
        dstW = maxW dstH = Math.round( maxW / aspectRatio) 
    } else { 
        dstH = maxH dstW = Math.round(maxH * aspectRatio) 
    }

    BufferedImage bi = new BufferedImage(dstW, dstH,   BufferedImage.TYPE_INT_RGB)            
    Graphics2D g2d = bi.createGraphics() g2d.drawImage(ai, 0, 0, dstW, dstH, null, null) 

    IIO.write( bi, 'JPEG', out )
} 

Answer 2

Use ImageTool plugin. http://grails.org/ImageTools+plugin

Answer 3

If you want to upload and scale JPEG images yourself, this blog post gives a pretty good overview

http://magicjavabeans.blogspot.com/2010/07/uploading-and-compressing-jpeg-images.html