Hello,

My program needs to open a given image file and determine the image format (e.g. JPG, TIF, BMP etc.). The files may not have extensions. I know that:

			

			String image_file_name = "e:\temp\images\000174E3";
			

			RenderedOp rop =  JAI.create("fileload", image_file_name);
			

		

will read a supported type, but I would like to know which type it is.

My reason for doing this is that I need to know the DPI of the image in order to show it at a percentage of the original scale as the images will mostly be scanned documents.

If I use:

			

			String op_name = rop.getOperationName();
			

		

I just get "fileload" - not very helpful. I have looked through the variables in the (Eclipse) debugger and the documentation and searched the net (for days), but cannot see anything which tells me what the image format is.

I do know that if I do:

			

			String[] names = rop.getPropertyNames();
			

		

on a TIFF image one of the properties will be tiff_directory which is quite helpful.

The JAI.create method seems to take a couple of seconds. As I am using this with a servlet app, if it is a JPEG image and doesn't need rotating or scaling, then I would rather not do JAI.create at all, but just open it with a SeekableStream and find the image format first, then decide what to do. Seems a pretty basic requirement to me.

Any comments or help much appreciated.

Regards, MarkW.