The API Doc for ImageReader.readRaster() claims that any registered IIOReadUpdateListener will be ignored when reading rasters using the image reader. This does not seem to be happening. For JPG, the buffered image passed to imageUpdate() method of IIOReadUpdateListener is null and hence does not serve any purpose. Such listener calls must be avoided. For BMP/ WBMP, the buffered images passed to imageUpdate() are valid. Hence if this behaviour is not going to be consistant across different reader implementation, the doc must be updated accordingly saying a reader implementation may choose to entertain/ignore the IIOReadUpdateListener depending on the format.

This is reproducible on all platforms since JDK1.4.

I have attached a sample code which would read a raster from the input source. Execute the sample code by passing different images such as JPG, BMP & WBMP and you would notice the above behavior.