binarize

Ibw = binarize(I::GMTimage, threshold::Int=0; band=1, threshold::Int=0, revert=false, bool::Bool=false) -> GMTimage

Ibw = binarize(I::GMTimage, threshold::Vector{Int}; band::Int=1, revert::Bool=false, bool::Bool=false)

Convert an image to a binary image (black-and-white) using a threshold.

Args

• I::GMTimage: input image of type UInt8.

• threshold: A number in the range [0 255]. If the default (0) is kept and the keyword threshold is not used, then the threshold is computed using the isodata method. Alternatively, a vector of two numbers in the range [0 255] can be used. In this case, the threshold is set to the first value and the second value is used to set the upper limit of the threshold range. That is, values between the two values are set to 255 and the rest to 0 (or true and false respectively when the bool keyword is set to true). Note that with this second form, the threshold keyword does not exist.

Kwargs

• band: If the I image has more than one band, use band to specify which one to binarize. By default the first band is used.

• bool: If true, the output image is of type Bool, otherwise it is of type UInt8.

• threshold: Alternative keyword argument to the positional threshold argument. Meaning, one can either use the binarize(I, ??) or binarize(I, threshold=??).

• revert: If true, values below the threshold are set to 255, and values >= the threshold are set to 0.

Return

A new GMTimage.

Example

using GMT

I = gdalread(GMT.TESTSDIR * "assets/coins.jpg");
Ibw = binarize(I, band=1)

# Show the two side-by-side
grdimage(I, figsize=6)
grdimage!(Ibw, figsize=6, xshift=6.1, show=true)

See Also