nQFactor

This parameter is used when saving an image file to FILE_CMP, FILE_JFIF, FILE_LEAD1JFIF, FILE_LEAD2JFIF, FILE_JTIF, FILE_LEAD1JTIF, FILE_LEAD2JTIF, FILE_FPX_JPEG_QFACTOR, and FILE_EXIF_JPEG. Qfactor is a number that determines the degree of loss in the compression process.

For possible values, refer to Compression Quality Factors.