


                                  - 1 -



       COMMAND

       mmmmaaaayyyyaaaannnn,,,, mmmmoooodddduuuulllloooo ---- sssstttteeeeppppppppeeeedddd ssssuuuurrrrffffaaaacccceeee ssssppppeeeecccciiiiaaaallll eeeeffffffffeeeeccccttttssss

       USAGE

       mmmmaaaayyyyaaaannnn [----tttt[uuuuiiiiddddsssscccc] _l_t__s_t_e_p] [----gggg[uuuuiiiiddddsssscccc] _l_g__s_t_e_p]

       mmmmoooodddduuuulllloooo [----tttt[uuuuiiiiddddsssscccc] _l_t__r_m_o_d] [----gggg[uuuuiiiiddddsssscccc] _l_g__r_m_o_d]

       DESCRIPTION

       MMMMaaaayyyyaaaannnn and mmmmoooodddduuuulllloooo are somewhat similar commands which will
       enable you to generate interesting and artistically pleasing
       renderings of _E_c_h_o images.  With these commands you can
       generate a variety of stepped effect patterns over selected
       regions of an image surface as well as blended transitions
       from one to the other.

       Each of these commands groups the image data in a
       characteristic way intended to emulate and dramatize a
       particular aspect of the "digital" effect surface patterning
       that results when image data is restricted to a limited
       number of discrete values.  The fundamental mode of the
       mmmmoooodddduuuulllloooo command is that of inducing the characteristic
       appearance of terraced landscapes, imagescapes in this case,
       by simply restricting radii to discrete modular integer
       values.

       The mmmmaaaayyyyaaaannnn command on the other hand induces a distinct
       banding of the "terraced" effect having a strong orientation
       in the axial and/or azimuthal direction.  This effect is
       achieved by averaging the radial measurements along each
       longitude (latitude) over a user specified band of latitudes
       (longitudes) and adjusting each radius of that interval to
       the interval average.  These two fundamental modes can be
       applied in concert in which case the averaging process is
       done patchwise over your choice of patch size.  This results
       in a more faceted effect displaying strong banding in both
       the axial and azimuthal directions.

       The various options available to you in using these
       commands, perhaps in concert with other _E_c_h_o commands, will
       enable you to control such things as the characterisic theme
       of the effect, its placement, its relative intensity and the
       character of transitions from one treatment to another.  The
       meanings associated with the options available for
       controlling the effects of the mmmmaaaayyyyaaaannnn and mmmmoooodddduuuulllloooo commands
       are:













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       ----tttt        Identifies following arguments as _l_a_t_i_t_u_d_i_n_a_l
                 specifications.

       ----gggg        Identifies following arguments as _l_o_n_g_i_t_u_d_i_n_a_l
                 specifications.

       ----uuuu        Uniform application of effect.

       ----iiii        Increase weighting as index increases.

       ----dddd        Decrease weighting as index increases.

       ----ssss        Modulate effect with sine function.

       ----cccc        Modulate effect with cosine function.

       _l_t__s_t_e_p   Size of the step latitudinally.

       _l_g__s_t_e_p   Size of the step longitudinally.

       _l_t__r_m_o_d   Modulo of radius steps.

       _l_g__r_m_o_d   Modulo of radius steps.

       You will need to decide upon a basic theme and select at
       least one of the optional modes indicated for these
       commands.  The ----tttt option will result in an azumuthal banding
       effect and the width of the banding will be governed by your
       choice of _l_t__s_t_e_p.  The ----gggg option will result in
       longitudinal banding of a width governed by the llllgggg____sssstttteeeepppp you
       choose.

       The effect of your choice can be applied uuuuniformly thoughout
       the current lt/lg range window.  The effect can be applied
       in a manner which either iiiincreases linearly from nil to full
       effect or ddddecreases linearly from maximum to nil with either
       advancing longitude (----tttt case) or with advancing latitude (----gggg
       case).

       Furthermore, you can modulate the effect sinusoidally from
       maximum effect to nil (----cccc option) or from nil effet to
       maximum (----ssss option) with either advancing latitude (----tttt case)
       or with advancing longitude (----gggg) case).  Note that the the
       modulation in this instance is orthogonal to the banding.

       The demarcation between zones receiving differing treatment
       will need to be controlled by appropriate adjustment of your
       current latitude/longitude window so as to restrict the
       application of a particular effect to the region of the
       image lying within that window.












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       CAVEATS

       You will probably need to do some image tailoring prior to
       using this these commands, e.g., ttttoooouuuuppppeeeeeeee, ffffiiiillllllll, rrrrrrrraaaannnnggggeeee, etc.,
       in order to preclude some distracting treatments in certain
       boundary regions of the image.





















































