

                                   Exhibit 4.1

                          Amendment to Rights Agreement

                       ADVANCED MACHINE VISION CORPORATION
                          AMENDMENT TO RIGHTS AGREEMENT


       AMENDMENT,  dated  as of  December  22,  1998,  to  that  certain  RIGHTS
AGREEMENT,  dated as of February  27,  1998,  between  Advanced  Machine  Vision
corporation,  a California  corporation  (the  "Company"),  and  American  Stock
Transfer & Trust Company (the "Rights Agent").

       WHEREAS,  the Company and FMC Corporation ("FMC") entered into a Series B
Preferred Stock Purchase  Agreement as of October 14, 1998 pursuant to which the
Company  issued to FMC 119,106  shares of Series B Preferred  Stock  convertible
into 1,191,060 shares of Class A Common Stock of the Company;

       WHEREAS, the Company and FMC entered into an Option Agreement dated as of
October  14,  1998  pursuant  to which FMC has the option to  purchase  from the
Company  the  number  of  shares  of  Class A Common  Stock  equal to 15% of the
outstanding shares of Class A and Class B Common Stock on the exercise date;

       WHEREAS,  FMC may in the future desire to purchase  additional  shares of
Common Stock of the Company from persons other than the Company, which purchases
might  cause FMC to become  an  Acquiring  Person  under the  Rights  Agreement,
depending on the interpretation of the Rights Agreement; and

       WHEREAS,  the Board of  Directors  of the  Company  has  authorized  this
Amendment  to the  Rights  Agreement,  pursuant  to  Section  27 of  the  Rights
Agreement.

       NOW,  THEREFORE,  BE IT  RESOLVED,  that the Rights  Agreement  is hereby
amended to provide that FMC's purchase of up to 1,600,000  additional  shares of
Common  Stock  from  persons  other  than  the  Company  shall  not be  deemed a
Triggering  Event,  shall not cause FMC to become an Acquiring  Person and shall
not  entitle  the  holder of any  Rights  Certificates  to  exercise  any rights
evidenced thereby.

         IN WITNESS  WHEREOF,  the parties  hereto have caused this Amendment to
Rights  Agreement  to be duly  executed and  attested,  all as of the date first
above written.


ADVANCED MACHINE VISION CORPORATION         AMERICAN STOCK TRANSFER &
                                            TRUST COMPANY

    /s/ Alan R. Steel                            /s/ Herbert J. Lemmer
By:______________________________           By:_________________________________

Name:  Alan R.  Steel                       Name:  Herbert J. Lemmer

Title:  Vice President, Finance & CFO       Title:  Vice President


