There are 3 ways in which you can save a bitmap
- Right click on the bitmap in the bitmap gallery and select Save. This saves the whole bitmap at the same pixel size as the original. You can select to save in a wide variety of bitmap types. If you select JPEG it will re-compress the JPEG using the quality value as last set on the Export JPEG dialog.
- Double click on the bitmap to go into XPE, select the Save icon. You can save a PNG or JPEG. This will save it at the original pixel size. If you save as JPEG you have an interactive quality control (select Save Options from the save dialog) you get a compression / quality slider. If you adjust this the main window previews the actual quality of the saved image. Put the quality really low to see the JPEG artefacts.
- Select the bitmap on the page and Select File -> Export (Ctrl+Shift+E) This will save the bitmap at the dimensions shown on screen and NOT the original size.