pnmtojpeg

Convert PNM to JPEG

$ pnmtojpeg [input.pnm] > [output.jpg]

$ pnmtojpeg -quality [85] [input.pnm] > [output.jpg]

$ pnmtojpeg -progressive [input.pnm] > [output.jpg]

$ pnmtojpeg -optimize [input.pnm] > [output.jpg]

pnmtojpeg [options] [file]

pnmtojpeg converts PNM (PBM, PGM, PPM) images to JPEG/JFIF format. The -quality option controls the compression-to-quality tradeoff, with higher values producing larger files with better image quality.
The -progressive option creates progressive JPEGs that render in increasing detail during loading. The -optimize flag reduces file size by computing optimal Huffman coding tables. The -grayscale option forces single-channel output even for color inputs. Part of the Netpbm toolkit.

-quality n

Quality (0-100, default 75).

Create progressive JPEG.

Optimize Huffman tables.

Force grayscale output.

Force baseline JPEG.

jpegtopnm(1), pnmtopng(1)