function resize_image(image, max_width){
    var reducedImageView = Titanium.UI.createImageView({
        width: max_width
        height: 'auto',
        canScale: true,
        image: image
    });
    return reducedImageView.toBlob();
}

09-24 14:02:14.197: ERROR/TiUncaughtHandler(16495): (main) [724,20151] Sending event: exception on thread: main msg:java.lang.IllegalArgumentException: width and height must be > 0

5 Answers

• The argument image should be a UI.ImageView object.

  function resizeImage(image, maxWidth) {
      var tmp = image.toImage();
      var wid = tmp.width;
      var ht = tmp.height;
      var reduction;
      if(wid > ht) {
          reduction = maxWidth / wid;
          wid = maxWidth;
          ht = Math.round(ht * reduction);
      } else {
          reduction = maxWidth / ht;
          ht = maxWidth;
          wid = Math.round(wid * reduction);
      }
      image = Ti.UI.createImageView({
          image: tmp,
          width: wid,
          height: ht
      });
      return image;
  };
  

• I also tried using backgroundImage instead of image in the view. It crashes with both of toBlob and toImage.

• Hi Parand,

  my android app doesn't work in 1.4.1 for some reason so I'm still using 1.3 for android.

  I've posted the full code here http://pastie.org/1180130 Its hard to remember what I did but I think I have 2 versions of the image. One that's displayed on screen for the user to see and another slightly larger one that gets uploaded to the server. I've included the rescale and upload functions, the upload function sends the data to a php script which returns a JSON stream indicating success.

  Just gave it a quick test and they still work :) I hope they help you out.

• There is a built in function to do this for iOS only but you'll need to make your own module, but here are two functions to perform the resize in a custom android module. Appcelerator folks, here's your prompt to just pull code into your repo for android users wanting the same functionality.

  To future people reading this… sorry I can't share any more source than this. Good luck everyone!

  ... (Appcelerator module) ...
  
      //private utility function to create an image (in Ti) from a bitmap
      public KrollDict createDictForImage(Bitmap bmpInput)
      {
          KrollDict d = new KrollDict();
          d.put("x", 0);
          d.put("y", 0);
          d.put("width", bmpInput.getWidth());
          d.put("height", bmpInput.getHeight());
  
          KrollDict cropRect = new KrollDict();
          cropRect.put("x", 0);
          cropRect.put("y", 0);
          cropRect.put("width", bmpInput.getWidth());
          cropRect.put("height", bmpInput.getHeight());
          d.put("cropRect", cropRect);
          d.put("media", TiBlob.blobFromImage(getTiContext(), bmpInput));
  
          return d;
      }
  
      //Methods
      @Kroll.method
      public KrollDict imageAsResized(@Kroll.argument(optional=false) KrollDict objImage, int iWidth, int iHeight) 
          throws IOException, IllegalStateException    
      {
          //decode the blob
          //if (blobInput.getType() != TiBlob.TYPE_IMAGE)   {
          //    throw new IOException("imageAsCropped::Input type of blob is not image");
          //}
          if (!objImage.containsKeyAndNotNull("media") 
              || !objImage.containsKeyAndNotNull("width") 
              || !objImage.containsKeyAndNotNull("height"))
          {
              throw new IllegalStateException("imageAsCropped::Failed, unknown image type!");
          }
          TiBlob blobInput = null;
          if (objImage.containsKey("media")) {
              Object media = objImage.get("media");
              if (media instanceof TiBlob) {
                  blobInput = (TiBlob) media;
              }
          }
  
          //decode the blob input
          byte[] byImage = blobInput.getBytes();
          Bitmap bmpInput = BitmapFactory.decodeByteArray(byImage, 0, byImage.length);
          Log.d(LCAT, "imageAsResized::Decoded "+byImage.length+" bytes from input blob");
          if (byImage.length==0 || bmpInput==null) {
              throw new IllegalStateException("imageAsCropped::Could not parse the input image in bytes");
          }
  
          //otherwise scale the bitmap with some java code...
          Bitmap bmpScaled = Bitmap.createScaledBitmap(bmpInput, iWidth, iHeight, false);
          //convert the scaled version back into a blob
          return createDictForImage(bmpScaled);
      }
  
      //config is a set of floats (x,y,width,height)
      @Kroll.method
      public KrollDict imageAsCropped(@Kroll.argument(optional=false) KrollDict objImage, 
                                   @Kroll.argument(optional=false) KrollDict config) 
          throws IOException, IllegalStateException 
      {
          double dX=0, dY=0, dWidth=0, dHeight=0;
  
          if (!objImage.containsKeyAndNotNull("media") 
              || !objImage.containsKeyAndNotNull("width") 
              || !objImage.containsKeyAndNotNull("height"))
          {
              throw new IllegalStateException("imageAsCropped::Failed, unknown image type!");
          }
          TiBlob blobInput = null;
          if (objImage.containsKey("media")) {
              Object media = objImage.get("media");
              if (media instanceof TiBlob) {
                  blobInput = (TiBlob) media;
              }
          }
  
          //decode the blob
          //if (blobInput.getType() != TiBlob.TYPE_IMAGE) {
          //    throw new IOException("imageAsCropped::Input type of blob is not image");
          //}
          if (!config.containsKeyAndNotNull("x") 
              || !config.containsKeyAndNotNull("y") 
              || !config.containsKeyAndNotNull("width") 
              || !config.containsKeyAndNotNull("height"))
          {
              throw new IllegalStateException("imageAsCropped::Failed, missing one parameter (x,y,width,height)");
          }
          dX = config.getDouble("x");
          dY = config.getDouble("y");
          dWidth = config.getDouble("width");
          dHeight = config.getDouble("height");
  
          //parse input into a regular image...
          byte[] byImage = blobInput.getBytes();
          Bitmap bmpInput = BitmapFactory.decodeByteArray(byImage, 0, byImage.length);
          Log.d(LCAT, "imageAsResized::Decoded "+byImage.length+" bytes from input blob");
          if (byImage.length==0 || bmpInput==null) {
              throw new IllegalStateException("imageAsCropped::Could not parse the input image in bytes");
          }
  
          // recreate the new Bitmap
          Bitmap bmpCropped = Bitmap.createBitmap(bmpInput, (int)dX, (int)dY,
                                                  (int)dWidth, (int)dHeight);
          //convert the scaled version back into a blob
          return createDictForImage(bmpCropped);
      }
  
  ...
  

• just had the same problem. try giving a different height, 'auto' doesn't work