Format. Choose the output format from the drop-down list. There are five possible formats. 
Note: the quality can be chosen for JPEG image output only.
JPEG Quality
Drag the slider to change the JPEG save quality. Use a value of 75 or more for images with sharply contrasting areas of color. To make the image even smaller reduce the image quality.
Note: reduced quality degrades the image.
A quality setting of 10 gives a very poor quality image that uses very little disk space. A quality of 75 gives a reasonable image that requires much less disk space, which will, in turn, load much faster on a web page. Although the image is in some way degraded, it is acceptable for the intended purpose.
Keep original quality
When checked, PhotoBulk will ignore the quality slider and try to save the converted image with the same JPEG quality/compression value as the original image. There is nothing much to be gained by saving a low-quality image at a high quality. Existing artefacts will not be removed, but the file size will increase substantially. 