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                                                                     EXHIBIT 3.1


                            CERTIFICATE OF AMENDMENT
                                       OF
                          CERTIFICATE OF INCORPORATION
                                       OF
                        PIA MERCHANDISING SERVICES, INC.


         The undersigned corporation, organized and existing under and by virtue
of the General Corporation Law of the State of Delaware does hereby certify as
follows:

         1. That Cathy L. Wood is the duly elected and acting Secretary and
Chief Financial Officer of PIA Merchandising Services, Inc., a Delaware
corporation (the "Corporation").

         2. That Article FIRST of the Certificate of Incorporation of the
Corporation is amended to read in full as follows:

            "FIRST: The name of the corporation is SPAR Group, Inc. (the
            "Corporation")."

         3. That Article FOURTH of the Certificate of Incorporation of the
Corporation is amended to read in full as follows:

            "FOURTH: The total number of shares of stock which the Corporation
            shall have the authority to issue is 50,000,000, consisting of
            47,000,000 shares of common stock, par value $.01 per share, and
            3,000,000 shares of preferred stock, par value $.01 per share. The
            preferred stock may be issued at any time, and from time to time, in
            one or more series pursuant hereto or to a resolution or resolutions
            providing for such issue duly adopted by the board of directors (the
            "Board") of the Corporation (authority to do so being hereby
            expressly vested in the Board), and such resolution or resolutions
            shall also set forth the voting powers, full or limited, or none, of
            each such series of preferred stock and shall fix the designations,
            preferences and relative, participating, optional or other special
            rights and qualifications, limitations or restrictions of each such
            series of preferred stock."

         4. That Article TENTH of the Certificate of Incorporation of the
Corporation is hereby deleted and Article ELEVENTH is hereby renumbered as
Article TENTH.

         5. That this Certificate of Amendment of Certificate of Incorporation
has been duly approved by the Board of Directors of the Corporation.

         6. That this Certificate of Amendment of Certificate of Incorporation
has been duly approved by the holders of a majority of the outstanding shares of
common stock, $.01 par value per share, of the Corporation in accordance with
the applicable provisions of Section 242 of the General Corporation Law of the
State of Delaware.




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         IN WITNESS WHEREOF, the Corporation has caused this Certificate to be
signed by Cathy L. Wood this 8th day July 1999.


                                       PIA MERCHANDISING SERVICES, INC.


                                       By: /s/ Cathy L. Wood
                                           -------------------------------------
                                           Cathy L. Wood,
                                           Secretary and Chief Financial Officer



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                          CERTIFICATE OF INCORPORATION
                                       OF
                        PIA MERCHANDISING SERVICES, INC.

         FIRST: The name of the corporation is PIA Merchandising Services, Inc.
(the "Corporation").

         SECOND: The address of the registered office of the Corporation in the
State of Delaware is Corporation Trust Center, 1209 Orange Street, in the City
of Wilmington, County of New Castle 19801. The name and address of the
Corporation's registered agent in the State of Delaware is The Corporation Trust
Company, Corporation Trust Center, 1209 Orange Street, in the City of
Wilmington, County of New Castle 19801.

         THIRD: The purpose of the Corporation is to engage in any lawful act or
activity for which a corporation may now or hereafter be organized under the
General Corporation Law of the State of Delaware.

         FOURTH: The total number of shares of stock which the Corporation shall
have authority to issue is 18,000,000, consisting of 15,000,000 shares of common
stock, par value $.01 per share, and 3,000,000 shares of preferred stock, par
value $.01 per share.

         FIFTH: The business and affairs of the Corporation shall be managed by
and under the direction of the Board of Directors. The exact number of directors
of the Corporation shall be fixed by or in the manner provided in the Bylaws of
the Corporation (the "Bylaws").

         SIXTH: In furtherance and not in limitation of the powers conferred by
statute, the Board of Directors is expressly authorized:

                (a) to adopt, repeal, rescind, alter or amend in any respect the
Bylaws, and to confer in the Bylaws powers and authorities upon the directors of
the Corporation in addition to the powers and authorities expressly conferred
upon them by statute;

                (b) from time to time to set apart out of any funds or assets of
the Corporation available for dividends an amount or amounts to be reserved as
working capital or for any other lawful purpose and to abolish any reserve so
created and to determine whether any, and, if any, what part, of the surplus of
the Corporation or its net profits applicable to dividends shall be declared in
dividends and paid to its stockholders, and all rights of the holders of stock
of the Corporation in respect of dividends shall be subject to the power of the
Board of Directors so to do;

                (c) subject to the laws of the State of Delaware, from time to
time to sell, lease or otherwise dispose of any part or parts of the properties
of the Corporation and to


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cease to conduct the business connected therewith or again to resume the same,
as it may deem best; and

                (d) in addition to the powers and authorities hereinbefore and
by the laws of the State of Delaware conferred upon the Board of Directors, to
execute all such powers and to do all acts and things as may be exercised or
done by the Corporation; subject, nevertheless, to the express provisions of
said laws, of the Certificate of Incorporation of the Corporation and its
Bylaws.

         SEVENTH: Meetings of stockholders of the Corporation may be held within
or without the State of Delaware, as the Bylaws may provide. The books of the
Corporation may be kept (subject to any provision of applicable law) outside the
State of Delaware at such place or places as may be designated from time to time
by the Board of Directors or in the Bylaws.

         EIGHTH: The Corporation reserves the right to adopt, repeal, rescind,
alter or amend in any respect any provision contained in this Certificate of
Incorporation in the manner now or hereafter prescribed by applicable law, and
all rights conferred on stockholders herein are granted subject to this
reservation.

         NINTH: A director of the Corporation shall not be personally liable to
the Corporation or its stockholders for monetary damages for breach of fiduciary
duty as a director, except for liability (i) for any breach of the director's
duty of loyalty to the Corporation or its stockholders, (ii) for acts or
omissions not in good faith or which involve intentional misconduct or a knowing
violation of law, (iii) under Section 174 of the Delaware General Corporation
Law, as the same exists or hereafter may be amended or (iv) for any transaction
from which the director derived an improper benefit. If the Delaware General
Corporation Law hereafter is amended to authorize the further elimination or
limitation of the liability of directors, then the liability of a director of
the Corporation, in addition to the limitation on personal liability provided
herein, shall be limited to the fullest extent permitted by the amended Delaware
Corporation Law. No amendment to or repeal of this Article Ninth shall apply to
or have any effect on the liability or alleged liability of any director of the
Corporation for or with respect to any acts or omissions of such director
occurring prior to such amendment or repeal.

         TENTH: No action required to be taken or which may be taken at any
annual or special meeting of stockholders of the Corporation may be taken
without a meeting, and the power of stockholders to consent in writing, without
a meeting, to the taking of any action is specifically denied.


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         ELEVENTH: The name and mailing address of the incorporator of the
Corporation are as follows:

                          Janis B. Salin, Esq.
                          c/o Riordan & McKinzie
                          300 South Grand Avenue, 29th Floor
                          Los Angeles, California 90071-3155

         I, the undersigned, being the incorporator hereinbefore named, for the
purpose of forming a corporation pursuant to the General Corporation Law of the
State of Delaware, do make this Certificate, hereby declaring and certifying
that this is my act and deed and the facts herein stated are true, and
accordingly have hereunto set my hand this 29th day of November, 1995.



                                            /s/ Janis B. Salin
                                            ------------------------------------
                                            Janis B. Salin, Incorporator





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                          AGREEMENT AND PLAN OF MERGER
                                     BETWEEN
                            PIA HOLDING CORPORATION,
                            A CALIFORNIA CORPORATION,
                                       AND
                        PIA MERCHANDISING SERVICES, INC.,
                             A DELAWARE CORPORATION

         THIS AGREEMENT AND PLAN OF MERGER (this "Merger Agreement") is entered
into as of this 22nd day of February, 1996 by and between PIA Holding
Corporation, a California corporation ("Merging Corporation"), and PIA
Merchandising Services, Inc., a Delaware corporation ("Surviving Corporation").

         1. Merging Corporation is authorized to issue 5,000,000 shares of
preferred stock, no par value (the "Merging Corporation Preferred Stock"), and
10,000,000 shares of common stock, no par value (the "Merging Corporation Common
Stock"). As of the date hereof, there are no shares of Merging Corporation
Preferred Stock outstanding and there are 3,563,929 shares of Merging
Corporation Common Stock outstanding.

         2. Surviving Corporation is authorized to issue 15,000,000 shares of
common stock, $.01 par value (the "Surviving Corporation Common Stock"), and
3,000,000 shares of preferred stock, $.01 par value (the "Surviving Corporation
Preferred Stock"). As of the date hereof, no shares of Surviving Corporation
Common Stock or Surviving Corporation Preferred Stock are outstanding.

         3. Merging Corporation shall be merged with and into Surviving
Corporation (the "Merger") in accordance with the California General Corporation
Law and the General Corporation Law of the State of Delaware and on the terms
and conditions hereinafter set forth. At the Effective Time of the Merger (as
hereinafter defined), the separate existence of Merging Corporation shall cease,
Surviving Corporation shall be the surviving corporation and Surviving
Corporation shall succeed, without other transfer, to all the rights and
property of Merging Corporation and shall be subject to all the debts and
liabilities thereof in the same manner as if Surviving Corporation had itself
incurred them. All rights of creditors and all liens put on the property of each
corporation shall be preserved unimpaired; provided that such liens upon
property of Merging Corporation shall be limited to the property affected
thereby immediately prior to the Effective Time of the Merger.

         4. At the Effective Time of the Merger, each share of Merging
Corporation Common Stock outstanding immediately prior to the Effective Time of
the Merger (collectively, the "Shares") shall be converted into one (1) share of
Surviving Corporation Common Stock.

         5. The conversion of Shares as provided in this Agreement shall occur
automatically upon the Effective Time of the Merger without action by the
holders thereof. Each holder of such Shares thereupon shall surrender his
certificate or certificates to Surviving


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Corporation and shall be entitled to receive in exchange therefor a certificate
or certificates representing the number of shares into which his Shares
theretofore represented by a certificate or certificates so surrendered shall
have been converted as aforesaid.

         6. As of the Effective Time of the Merger, Surviving Corporation will
assume and continue Merging Corporation's 1990 Stock Option Plan, as amended,
and the outstanding and unexercised portions of all options to buy Common Stock
of Merging Corporation shall become options to purchase the same number of
shares of Common Stock of Surviving Corporation as the number of shares of
Common Stock of Merging Corporation subject to such options, with no other
changes in the terms and conditions of such options, including exercise prices,
and, as of the Effective Time of the Merger, Surviving Corporation hereby
assumes the outstanding and unexercised portions of such options and the
obligations of Merging Corporation with respect thereto.

         7. As of the Effective Time of the Merger, Surviving Corporation will
assume all obligations under all outstanding warrants and other rights to
purchase shares of Common Stock of Merging Corporation, and the outstanding but
unexercised portions of all such warrants or other rights to purchase Common
Stock of Merging Corporation shall represent the right to acquire the same
number of shares of Common Stock of Surviving Corporation as the number of
shares of Common Stock of Merging Corporation then subject to such warrants or
other rights, with no other changes in the terms and conditions of such warrants
and other rights, including exercise prices.

         8. The Certificate of Incorporation and Bylaws of Surviving Corporation
as in effect at the Effective Time of the Merger shall continue to be the
Certificate of Incorporation and Bylaws of Surviving Corporation after
consummation of the Merger.

         9. From time to time as and when required by Surviving Corporation or
its successors or assigns, there shall be executed and delivered on behalf of
Merging Corporation such deeds and other instruments, and there shall be taken
or caused to be taken such further and other actions as shall be appropriate or
necessary in order to vest or perfect in or to confirm in record or otherwise in
Surviving Corporation the title to and possession of all the property, interest,
assets, rights, privileges, immunities, powers, franchises and authority of
Merging Corporation, and otherwise to carry out the purposes of this Merger
Agreement, and the officers and directors of Surviving Corporation are fully
authorized in the name and on behalf of Merging Corporation or otherwise to take
any and all such actions and to execute and deliver any and all such deeds and
other instruments.

         10. Prior to the filing of this Merger Agreement with the Secretary of
Sate of the State of California and with the Secretary of State of the State of
Delaware, this Merger Agreement may be amended by written agreement of the
boards of directors of Merging Corporation and Surviving Corporation, or by
their respective officers authorized by such boards


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of directors, notwithstanding approval of this Merger Agreement by the
shareholders of Merging Corporation.

         11. The effective date of the Merger is February 22, 1996 (the
"Effective Time of the Merger").

         12. This Merger Agreement may be executed in any number of
counterparts, each of which shall be deemed to be an original.

         IN WITNESS WHEREOF, the parties have caused this Agreement and Plan of
Merger to be executed as of the date first above written.

                                        PIA HOLDING CORPORATION,
                                        a California corporation


                                        By: /s/ Larry M. Dorr
                                            -----------------------------------
                                            Larry M. Dorr
                                            Executive Vice President

Attest:


/s/ Patrick C. Haden
- ---------------------------------
Patrick C. Haden
Secretary

                                        PIA MERCHANDISING SERVICES, INC.,
                                        a Delaware corporation


                                        By: /s/  Larry M. Dorr
                                            ------------------------------------
                                            Larry M. Dorr
                                            Executive Vice President

Attest:


/s/ Patrick C. Haden
- ---------------------------------
Patrick C. Haden
Secretary



                                       3.

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                             CERTIFICATE OF APPROVAL
                                       OF
                          AGREEMENT AND PLAN OF MERGER
                                       BY
                        PIA MERCHANDISING SERVICES, INC.



         Larry M. Dorr and Patrick C. Haden hereby certify that:

         1. They are the Executive Vice President and the Secretary,
respectively, of PIA Merchandising Services, Inc., a Delaware corporation (the
"Surviving Corporation").

         2. The Agreement and Plan of Merger in the form attached was duly
approved by the Board of Directors of the Surviving Corporation.

         3. No shares of stock of the Surviving Corporation have been issued.

         We further declare under penalty of perjury under the laws of the State
of California that the matters set forth in this certificate are true and
correct of our own knowledge.

Date: February 22, 1996


                                             /s/  Larry M. Dorr
                                             -----------------------------------
                                             Larry M. Dorr
                                             Executive Vice President


                                             /s/ Patrick C. Haden
                                             -----------------------------------
                                             Patrick C. Haden
                                             Secretary