The JWIC wavelet translator (available on BeBits) is a good BeOS citizen: it updates its settings as soon as you change them, so you can click Settings, change the image quality, click Save, change the image quality, change the filename and click Save again and compare the results. The jpeg translator is not such a good BeOS citizen (even though it's provided by Be!) because you need to close its Settings window for the settings to take effect. To compare different qualities of images, you need to press Settings, set the quality in the Settings dialogue, close the Settings dialogue, press Save, then press Settings to change the quality again, and close the Settings dialogue again before saving.