Here's the information generated when you run "nconvert -help":

** NCONVERT v2.80 Copyright 1991-99 Pierre-E Gougelet (Oct 22 1999/16:44:57) **
        Version for Windows 95/98/NT  (All rights reserved)
** This is a freeware software

The JPEG code is based in part on the work of the Independent JPEG Group's software.
The PNG code is based in part on the work of the Group 42, Inc.

This software is based in part on compression library of Jean-loup Gailly and Mark Adler

Usage : NCONVERT.EXE [options] file ...

        Options :
          -quiet            : Quiet mode
          -v[.]             : Verbose
          -in format        : Input format number or name
          -npcd num         : PCD 0:768x512 (default), 1:384x256, 2:192x128
          -ngrb npic        : HP-48 number of grey : 1, 2 or 4 (default : 1)
          -ctype type       : Channel Type (Raw)
              grey  : Greyscale (default)
              rgb   : Red,Green,Blue
              bgr   : Blue,Green,Red
               rgba  : Red,Green,Blue,Alpha
              abgr  : Alpha,Blue,Green,Red
              cmy   : Cyan,Magenta,Yellow
              cmyk  : Cyan,Magenta,Yellow,Black
          -corder order     : Channel Order (Raw)
              inter : Interleaved (default)
              seq   : Sequential 
              sep   : Separate
          -size geometry    : Width and height (Raw/YUV)
                Geometry is widthxheight+offset
          -n start end step : Begin End Step (for image sequence)
          -o filename       : Output filename
              Use # to specify position of numeric enumerator
              Use to specify source filename
          -out format       : Output format number or name
          -D                : Delete original picture
          -c value          : Compression number (default : 0)
          -q value          : JPEG/PNG quality (default : 100)
          -i                : Interlaced GIF / Progressive JPEG

        Process :
          -average size     : Average (3,5,7,9,11,13)
          -balance r g b    : Color balance
          -binary dither    : Convert in Binary
              pattern : Ordered pattern
              floyd   : Floyd steinberg
              halft45 : Halftone 45
              halft90 : Halftone 90
          -blur percent     : Blur (1...100)
          -brightness value : Modify brightness (-100...100)
          -canvas w h       : Resize canvas
              w h can be percent (ex: -resize 100% 200%)
          -colors num       : Convert in Indexed Colors (256, 216, 128, 64, 32, 16 or 8)
          -contrast value   : Modify contrast (-100...100)
          -crop x y w h     : Crop
          -dither           : Use dither for conversion (Colors and Grey only)
          -edetail          : Enhance detail
          -eedge percent    : Enhance edges (1...100)
          -edgedetect type  : Edge detect
              light/medium/heavy
          -efocus           : Enhance focus
          -emboss           : Emboss 
          -embossmore       : Emboss more
          -equalize         : Equalize
          -frestore         : Focus restoration
          -gamma value      : Modify gamma (0.01<->5.0
          -gauss size       : Blur gaussian (3,5,7,9,11,13)
          -grey num         : Convert in Grey Scale (256, 128, 64, 32, 16, 8 or 4)
          -lens percent     : Lens (1...100)
          -log              : Apply logarithmic correction
          -maximum size     : Maximum filter (3,5,7,9,11,13)
          -medianb size     : Median Box filter (3,5,7,9,11,13)
          -medianc size     : Median Cross filter (3,5,7,9,11,13)
          -minimum size     : Minimum filter (3,5,7,9,11,13)
          -mosaic size      : Mosaic (1...64)
          -negate           : Negate
          -noise reduce     : Reduce noise
          -noise type value 
              uniform   : Add uniform noise
              gaussian  : Add gaussian noise
              laplacian : Add laplacian noise
              poisson   : Add poisson noise
          -normalize        : Normalize
          -oil size         : Oilify (1...16)
          -posterize count  : Posterize (2...256)
          -ratio            : Keep the ratio for scaling
          -rtype            : Type of resampling (default : linear)
              quick  : Quick resize
              linear : Bi-linear
          -resize w h      : Scale width-height
              w h can be percent (ex: -resize 100% 200%)
          -rotate degrees   : Rotate
          -sharpen percent  : Sharpen (1...100)
          -shear            : Shear
          -slice            : Slice
          -soften percent   : Soften (1...100)
          -solarize value   : Solarize (1...255)
          -spread amount    : Spread (1...32)
          -swap type        : Swap component
              rbg   : RGB->RBG
              bgr   : RGB->BGR
              brg   : RGB->BRG
              grb   : RGB->GRB
              gbr   : RGB->GBR
          -swirl degrees    : Swirl (1...360)
          -tile size        : Tile (1...64)
          -truecolors       : Convert in True Colors
          -xflip            : Flip horizontal
          -yflip            : Flip vertical
          -waves wavelength phase amount : Waves
              wavelength   : (1.0 50.0)
              phase        : (0.0 360.0)
              amount       : (0.0 100.0)

        Available format:
               Num  Name     Write  Description
                -1                : Automatic (Only for input)
                 0 [jpeg    ]  *  : JPEG v6.0 
                 1 [tga     ]  *  : Truevision Targa 
                 2 [tdi     ]     : Explore (TDI) & Maya 
                 3 [soft    ]  *  : Softimage 
                 4 [sgi     ]  *  : RGB Silicon Graphics 
                 5 [tiff    ]  *  : TIFF Revision 6 
                 6 [vista   ]  *  : Vista 
                 7 [ras     ]     : Sun Rasterfile 
                 8 [pict    ]     : Macintosh Quickdraw/Pict 
                 9 [alias   ]  *  : Alias Image File 
                10 [bmp     ]  *  : Windows & OS/2 Bitmap 
                11 [iff     ]  *  : Amiga IFF (ILBM & LBM) 
                12 [png     ]  *  : Portable Network Graphics 
                13 [gif     ]  *  : CompuServe GIF 
                14 [pcx     ]  *  : Zsoft Publisher's Paintbrush 
                15 [dcx     ]     : Zsoft Multi-page Paintbrush 
                16 [pnm     ]  *  : Portable Image 
                17 [rla     ]  *  : Wavefront Raster file 
                18 [rle     ]     : Utah raster image 
                19 [pixar   ]     : Pixar picture file 
                20 [taac    ]     : Sun TAAC file 
                21 [miff    ]  *  : Image Magick file 
                22 [psd     ]     : Adobe Photoshop Document 
                23 [psp     ]     : Paint Shop Pro 
                24 [sfw     ]     : Seattle Film Works 
                25 [pwp     ]     : Seattle Film Works multi-image 
                26 [scitex  ]     : SciTex 
                27 [hru     ]  *  : HRU 
                28 [gem     ]     : Digital Research (GEM Paint) 
                29 [dkb     ]  *  : DKB & Qrt Ray-Tracer 
                30 [cloe    ]     : Cloe Ray-Tracer 
                31 [vivid   ]  *  : Vivid Ray-Tracer 
                32 [mtv     ]  *  : MTV & Rayshade 
                33 [cp8     ]     : CP8 256 Gray Scale 
                34 [speed   ]     : Image Speeder 
                35 [xbm     ]  *  : X11 Bitmap 
                36 [xpm     ]  *  : X11 Pixmap 
                37 [icon    ]     : Sun Icon/Cursor 
                38 [ico     ]  *  : Windows Icon 
                39 [cur     ]     : Windows Cursor 
                40 [clp     ]     : Windows Clipboard 
                41 [cdr     ]     : Corel Draw bitmap 
                42 [fbm     ]     : Fuzzy bitmap 
                43 [pm      ]     : PM 
                44 [cam     ]     : Casio QV-10/100 Camera 
                45 [j6i     ]     : Ricoh Digital Camera 
                46 [kdc     ]     : Kodak DC120 Digital Camera 
                47 [tim     ]     : Sony Playstation TIM 
                48 [fits    ]     : Flexible Image Transport System 
                49 [synu    ]     : Synthetic Universe 
                50 [pcd     ]     : Kodak Photo CD 
                51 [xcf     ]     : Gimp Bitmap 
                52 [gbr     ]     : Gimp Brush 
                53 [pat     ]  *  : Gimp Pattern 
                54 [gicon   ]     : Gimp Icon 
                55 [psion3  ]  *  : Psion Serie 3 Bitmap 
                56 [psion5  ]  *  : Psion Serie 5 Bitmap 
                57 [palm    ]  *  : Palm Pilot 
                58 [grob    ]  *  : HP-48 GROB 
                59 [ti      ]  *  : TI Bitmap 
                60 [vicar   ]     : Vicar 
                61 [stx     ]     : SBIG CCD camera ST-X 
                62 [viff    ]     : Khoros Visualization image file 
                63 [xim     ]     : Xim 
                64 [vpb     ]     : Quantel VPB 
                65 [fit     ]     : FIT 
                66 [degas   ]  *  : Degas & Degas Elite 
                67 [neo     ]     : Neochrome (ST & TT) 
                68 [zzrough ]     : ZZ Rough 
                69 [dali    ]     : Dali Raw 
                70 [stad    ]     : Stad 
                71 [gfaray  ]     : Gfa Raytrace 
                72 [spu     ]     : Spectrum 512 
                73 [spc     ]     : Spectrum 512 (Compressed) 
                74 [sps     ]     : Spectrum 512 (Smooshed) 
                75 [rix     ]     : ColoRIX 
                76 [cmu     ]     : CMU Window Manager 
                77 [xwd     ]     : X Windows System dump 
                78 [pic     ]     : PC Paint / Pictor Page 
                79 [ilab    ]     : ImageLab 
                80 [msp     ]     : Microsoft Paint 
                81 [calamus ]     : Calamus 
                82 [art     ]     : Artisan 
                83 [aurora  ]     : Aurora 
                84 [qdv     ]     : Qdv (Random Dot Software) 
                85 [tdim    ]     : Digital F/X 
                86 [tdim    ]     : Electric Image 
                87 [biorad  ]     : Biorad 
                88 [bob     ]     : Bob Raytracer 
                89 [face    ]     : Usenix FaceServer 
                90 [eps     ]     : Encapsulated Postscript(Preview) 
                91 [wpg     ]     : Word Perfect Graphics 
                92 [cut     ]     : Dr Halo 
                93 [dbw     ]     : DBW Render 
                94 [acorn   ]     : Acorn Sprite 
                95 [avs     ]     : Stardent AVS X 
                96 [aim     ]     : AIM Grey Scale 
                97 [mac     ]     : Mac Paint 
                98 [tiny    ]     : Tiny 
                99 [doodle  ]     : Doodle 
               100 [artdir  ]     : Art Director 
               101 [z80scr  ]     : Z80 Screen dump 
               102 [z80sna  ]     : Z80 Spectrum Snapshot 
               103 [fax     ]     : Fax G3 
               104 [uyvyi   ]  *  : YUV 16Bits Interleaved 
               105 [uyvy    ]  *  : YUV 16Bits 
               106 [yuv411  ]     : YUV 4:1:1 
               107 [yuv422  ]     : YUV 4:2:2 
               108 [yuv444  ]     : YUV 4:4:4 
               109 [raw     ]     : Raw 
