This function can read an image file from the hard disk and plot it in a newly-opened graphics device.
ring_read(img, dpi = NULL, RGB = c(0.299, 0.587, 0.114), plot = FALSE, rotate = 0, magick = TRUE)
A character string indicating the path of the image file. Supported formats include png, tiff, jpg and bmp.
An integer specifying the dpi of the image file. A minimum of 300 dpi is required when running automatic detection.
A numeric vector of length 3 giving the weight of RGB channels.
An integer specifying how many degrees to rotate (clockwise).
It requires one of the following values:
A logical value. If
A magick image object containing the image data.
Proper image preparation has a great influence on the measurement of ring widths. A tree-ring image should not contain irrelevant or redundant features, such as wooden mounts where cores are glued. The larger the file size of an image, the slower the image processing operation will be.
Pith side of a wood sample should be placed on the right side
of a graphics window. Use
rotate to change its position.
It is highly recommended to use the default value
magick = TRUE,
magick can significantly reduce the memory usage
when reading a large file.
If image data is stored in a non-standard format, image reading may fail.
In that case you can set
magick = FALSE to
avoid the use of
img.path <- system.file("001.png", package = "MtreeRing") ## Read and plot the image: t1 <- ring_read(img = img.path, dpi = 1200, plot = TRUE)