this.readerSpiName = readerSpi.getClass().getName();
            this.writerSpiName = writerSpi.getClass().getName();
        }
        public boolean filter(Object elt) {
            ImageTranscoderSpi spi = (ImageTranscoderSpi)elt;
            String readerName = spi.getReaderServiceProviderName();
            String writerName = spi.getWriterServiceProviderName();
            return (readerName.equals(readerSpiName) &&
                    writerName.equals(writerSpiName));
        }