get_coord: Get coordinates from image of points

In privefl/img2coord: Coordinates of Points from an Image

Description

Get coordinates from image of points

Usage

get_coord(input, x_ticks, y_ticks, K, K_min = K, K_max = K,
  max_pixels = 10000, plot = TRUE)

Arguments

input	Path to image or directly a Magick image.
x_ticks	Values of all ticks of the x axis.
y_ticks	Values of all ticks of the y axis.
K	Number of points in the image. Use K_min and K_max if you only know an interval.
K_min	Minimum number of points in the image.
K_max	Maximum number of points in the image.
max_pixels	Maximum number of pixels representing points.
plot	Whether to plot centers on the image? Default is TRUE.

Value

A list of coordinates. There is also an attribute "stat" which was used to guess the number of points in the image.

Examples

# Create some image
file <- tempfile(fileext = ".png")
png(file, width = 600, height = 400)
plot(y <- c(0, runif(20), 1))
dev.off()

# Get coordinates
(coord <- get_coord(file, seq(5, 20, 5), seq(0, 1, 0.2),
                    K_min = 10, K_max = 30))
round(coord$x, 2)
plot(coord$y, y, pch = 20, cex = 1.5); abline(0, 1, col = "red")

# When the image is too large, you can downsize it
(coord2 <- file %>% img_read() %>% img_scale(0.7) %>%
    get_coord(seq(5, 20, 5), seq(0, 1, 0.2), K_min = 10, K_max = 30))
round(coord2$x, 2)
plot(coord2$y, y, pch = 20, cex = 1.5); abline(0, 1, col = "red")

privefl/img2coord documentation built on May 17, 2019, 10:39 a.m.