Draw Text on an Image

drawText draws text over an Image object. This operation is destructive: it changes irreversibly the Image object and cannot be undone.

Usage

drawText(
  image,
  text,
  x,
  y,
  font_face = "simplex",
  font_scale = 1,
  italic = FALSE,
  color = "red",
  thickness = 1,
  bl_orig = TRUE
)

Arguments

image

An Image object.

text

A character string representing the text to be drawn.

x

A numeric value representing the x coordinate of the bottom left corner of the text string (or top left if bl_orig == TRUE).

y

A numeric value representing the y coordinate of the bottom left corner of the text string (or top left if bl_orig == TRUE).

font_face

A character string representing the font type of the text (default: "simplex"). See notes for a list of available font types.

font_scale

A numeric value representing the scale factor by which the font-specific base size is multiplied (default: 1).

italic

A logical specifying whether the text should italicized (default: FALSE).

color

Any kind of R color specification compatible with col2bgr representing the color of the line (default: "red").

thickness

A numeric value representing the thickness in pixels of the line (default: 1).

bl_orig

A logical specifying the origin of the text drawing (default: TRUE). If TRUE, the text is drawn right-side-up. If FALSE, it is drawn upside-down.

Value

This function does not return anything. It modifies image in place.

See also

Image, getTextSize

Author

Simon Garnier, garnier@njit.edu

Examples

balloon <- image(system.file("sample_img/balloon1.png", package = "Rvision"))
drawText(balloon, "I'm a balloon", 50, 50, thickness = 3)