Thanks Galfar, it's working now.

OS=Windows XP professional, using FPC compiler.  In Imagingjpeg.pas I find the following lines just before the interface comand:

{ Automatically use FPC's PasJpeg when compiling with Lazarus.}

{$IFDEF LCL}
  {$UNDEF IMJPEGLIB}
  {$DEFINE PASJPEG}
{$ENDIF}

interface

So it seems that IMJPEGLIB is automatically undefined since I have LCL defined for FPC.

In dzlib.pas I fine the lines:

{ Automatically use FPC's PasZLib when compiling with Lazarus.}

{$IFDEF LCL}
  {$UNDEF IMPASZLIB}
  {$DEFINE FPCPASZLIB}
{$ENDIF}

uses
     
So again, a similar problem.

Mark

I get the following compiler errors:

lclimager.lpr(23,1) Error: Undefined symbol: IMJCOMAPI_JPEG_DESTROY$J_COMMON_PTR
lclimager.lpr(23,1) Error: Undefined symbol: IMJDAPIMIN_JPEG_DESTROY_DECOMPRESS$J_DECOMPRESS_PTR
lclimager.lpr(23,1) Error: Undefined symbol: IMJCAPIMIN_JPEG_DESTROY_COMPRESS$J_COMPRESS_PTR
lclimager.lpr(23,1) Error: Undefined symbol: IMJDMARKER_JPEG_RESYNC_TO_RESTART$J_DECOMPRESS_PTR$LONGINT$$BOOLEAN
lclimager.lpr(23,1) Error: Undefined symbol: IMJDAPIMIN_JPEG_CREATEDECOMPRESS$J_DECOMPRESS_PTR$LONGINT$LONGINT
lclimager.lpr(23,1) Error: Undefined symbol: IMJDAPIMIN_JPEG_READ_HEADER$J_DECOMPRESS_PTR$BOOLEAN$$LONGINT
lclimager.lpr(23,1) Error: Undefined symbol: IMJCAPIMIN_JPEG_CREATECOMPRESS$J_COMPRESS_PTR$LONGINT$LONGINT
lclimager.lpr(23,1) Error: Undefined symbol: IMJCPARAM_JPEG_SET_DEFAULTS$J_COMPRESS_PTR
lclimager.lpr(23,1) Error: Undefined symbol: IMJCPARAM_JPEG_SET_QUALITY$J_COMPRESS_PTR$LONGINT$BOOLEAN
lclimager.lpr(23,1) Error: Undefined symbol: IMJCPARAM_JPEG_SET_COLORSPACE$J_COMPRESS_PTR$J_COLOR_SPACE
lclimager.lpr(23,1) Error: Undefined symbol: IMJCPARAM_JPEG_SIMPLE_PROGRESSION$J_COMPRESS_PTR
lclimager.lpr(23,1) Error: Undefined symbol: IMJDAPISTD_JPEG_START_DECOMPRESS$J_DECOMPRESS_PTR$$BOOLEAN
lclimager.lpr(23,1) Error: Undefined symbol: IMJDAPISTD_JPEG_READ_SCANLINES$J_DECOMPRESS_PTR$JSAMPARRAY$LONGWORD$$LONGWORD
lclimager.lpr(23,1) Error: Undefined symbol: IMJDAPISTD_JPEG_FINISH_OUTPUT$J_DECOMPRESS_PTR$$BOOLEAN
lclimager.lpr(23,1) Error: Undefined symbol: IMJDAPIMIN_JPEG_FINISH_DECOMPRESS$J_DECOMPRESS_PTR$$BOOLEAN
lclimager.lpr(23,1) Error: Undefined symbol: IMJCAPISTD_JPEG_START_COMPRESS$J_COMPRESS_PTR$BOOLEAN
lclimager.lpr(23,1) Error: Undefined symbol: IMJCAPISTD_JPEG_WRITE_SCANLINES$J_COMPRESS_PTR$JSAMPARRAY$LONGWORD$$LONGWORD
lclimager.lpr(23,1) Error: Undefined symbol: IMJCAPIMIN_JPEG_FINISH_COMPRESS$J_COMPRESS_PTR
lclimager.lpr(23,1) Error: Undefined symbol: TC_IMPASZLIB_ZLIB_VERSION
lclimager.lpr(23,1) Error: Undefined symbol: IMPASZLIB_DEFLATEINIT_$Z_STREAM$LONGINT$ANSISTRING$LONGINT$$LONGINT
lclimager.lpr(23,1) Error: Undefined symbol: IMZDEFLATE_DEFLATE$Z_STREAM$LONGINT$$LONGINT
lclimager.lpr(23,1) Error: Undefined symbol: IMZDEFLATE_DEFLATEEND$Z_STREAM$$LONGINT
lclimager.lpr(23,1) Error: Undefined symbol: IMPASZLIB_INFLATEINIT_$Z_STREAM$ANSISTRING$LONGINT$$LONGINT
lclimager.lpr(23,1) Error: Undefined symbol: IMZINFLATE_INFLATE$Z_STREAM$LONGINT$$LONGINT
lclimager.lpr(23,1) Error: Undefined symbol: IMZINFLATE_INFLATEEND$Z_STREAM$$LONGINT
lclimager.lpr(23,1) Error: Undefined symbol: IMZINFLATE_INFLATERESET$Z_STREAM$$LONGINT
lclimager.lpr(23,1) Fatal: There were 26 errors compiling module, stopping

Any suggestions?