thresh                package:EBImage                R Documentation

_I_m_a_g_e _a_n_d _c_o_l_o_r _c_h_a_n_n_e_l _t_h_r_e_s_h_o_l_d_i_n_g

_D_e_s_c_r_i_p_t_i_o_n:

     Functions to threshold images and color channels of images.

_U_s_a_g_e:

       ## S4 method for signature 'Image':
       thresh(x, w=5, h=5, offset=0.01, ...)
       ## S4 method for signature 'Image':
       athresh(x, w=10, h=10, offset=0, ...)
       ## S4 method for signature 'Image':
       cthresh(x, threshold=0, ...)
       

_A_r_g_u_m_e_n_t_s:

       x: An object of 'Image'. For 'thresh' it must be in the
          'Grayscale' mode. 

    w, h: Thresholding frame width and height in pixel. 

  offset: Threshold offset from the mean value. 

threshold: Threshold value for channel thresholding (uniform). 

     ...: Reserved. 

_D_e_t_a_i_l_s:

     If 'thresh' and 'athresh' are adaptive thresholind functions.
     While 'athresh' can be used on both 'Grayscale' and  'TrueColor'
     images, 'thresh' can only be used on  'Grayscale' images, however
     it is significantly faster on them.

     The value of 'offset' in 'thresh' is on the same scale as data,
     i.e. the default value is selected assuming data in the range
     '[0,1]'. This value for 'athresh' should be selected empirically,
     as this function uses 'AdaptiveThreshold' of 'ImageMagick' and the
     scale of this parameter was not documented; the reasonable values
     are usually in the orders of 500, 1000 or avobe (at least to
     obtain similar thresholding to that of 0.01 with 'thresh' on
     cytomicroscopic images. ).

_V_a_l_u_e:

     A new instance of 'Image' in the same color mode as input.

_A_u_t_h_o_r(_s):

     Oleg Sklyar, osklyar@ebi.ac.uk,  2005-2007

_R_e_f_e_r_e_n_c_e_s:

     _ImageMagick_: <URL: http://www.imagemagick.org>.

_S_e_e _A_l_s_o:

     ' Image, Image, distmap, segment,  [,Image-method '

_E_x_a_m_p_l_e_s:

       ## see example(watershed)

