image uploading not working in spring

I have a spring2.0 application and we are using uploadify jquery plugin 2.1 version to implement the image upload functionality.

Problem is: when I am trying to upload any image in java code it is saying it's resolution is 0dpi. But i checked i was 300dpi. Why is it happening? My uploadify configuration is:

$('#imageFile1').uploadify({
'uploader'  : '../uploadify/uploadify.swf',
'script'    : 'images.htm',
'scriptData'    : {'currentFormSpecId' : '${myCommand.formId}'},
'cancelImg' : 'cancel.png',
'auto'      : false,
'multi'     : true,
'wmode'     : 'transparent',
'width'     : 130,
'queueID'   : 'fileQueue',
'queueSizeLimit'    : 15,
'folder'    : '../uploadify',
'fileDesc'  : '*.jpg;*.jpeg;*.tif;*.tiff;*.eps',
'fileExt'   : '*.jpg;*.jpeg;*.tif;*.tiff;*.eps',
'sizeLimit' : 102400000,
'onError': function(event, queueID, fileObj, errorObj) {
// Error display
},
'onComplete': function(event, queueID, fileObj, response, data) {
//success display

});

Java code

    public ModelAndView uploadImagesToDisk (HttpServletRequest request,
            HttpServletResponse response, Object command, BindException errors) throws Exception {
        String currentFormId = request.getParameter("currentFormSpecId");

        DefaultMultipartHttpServletRequest multipartHttpServletRequest = 
                (DefaultMultipartHttpServletRequest) request; 

        MultipartFile multipartFile = multipartHttpServletRequest.getFile("Filedata");

        OutputStream outputStream = null;

        try {
            String imageFileName = multipartFile.getOriginalFilename();
            String imageFileExtension = getFileExtension(multipartFile);
            Image image =  Image.getInstance(multipartFile.getBytes());
        if ((image.getDpiX() < MINIMUM_DPI) || (image.getDpiY() < MINIMUM_DPI)) {
            throw new Exception("ERROR: The image (" + multipartFile.getOriginalFilename() 
                    + ", " + image.getDpiX() + " dpi) " + 
                    " your are attempting to upload does not meet the requirements " +
            "for minimum resolution of 300 dpi. Please upload another image.");
        }

}

in above code image.getDpiX() is always coming zero.

one more weird thing I noticed: When I checked the image resolution in my window7 machine it is saying it is 300dpi but when I am checking the same image in windows server machine(using citrix I am connecting and it has low screen resolution), it is showing 96dpi. Why is it happening?

Please let me know you want me to post anything else.