cpp_draw {IFC} | R Documentation |
Draw Shape to Image
Description
low-level function to add shape on image
Arguments
img |
an IntegerVector. A non null array of dimensions [nrow, ncol, 4]. |
coords |
an IntegerMatrix whose rows are points to draw and with: |
mask |
a LogicalMatrix where every true value will be added to the image. |
color |
a 4 rows IntegerMatrix specifying rgba, from 0 to 255. |
blur_size |
a R_len_t the size of the gaussian blurring kernel. Default is 9. |
blur_sd |
a double the sd of the gaussian blurring kernel. Default is 3.0. |
Details
shape according to 'mask' will be drawn on 'img' centered at coordinates coords[, 1], coords[, 0] and every pixels being part of the shape will be filled with 'color'. If only one 'color' is provided, this 'color' will be used for each points. If more than one 'color' is provided, then if number of colors (ncol) equals the number of points 'color' will be used as is for each single point. Otherwise, 'color' will be considered as a color-gradient and density will be computed. /!\ please note that IFC:::densCols() is faster to compute color based on density for n < 20000 points, so it's worth using it when number of points are lower.
Value
/!\ nothing is returned but img is modified in-place