[syslinux] How to convert jpg into lss format

[BM Shukla]

I would like to to know about conversion from jpg file to lss format.
I used ppmtolss16. It is giving following errors.

for .jpg file:
ppmtolss16: stdin is not a raw PPM file at ppmtolss16 line 105, <STDIN> 
line 1.
for .png files:
ppmtolss16: stdin is not a raw PPM file at ppmtolss16 line 105, <STDIN> 
line 1.
from .ppm file: ( I converted .jpg file in to .ppm file using irfanview)
ppmtolss16: stdin is not a raw PPM file at ppmtolss16 line 105, <STDIN> 
line 1.

I need a solution to it.

Thanks.

BM Shukla