mrjoh3 / georefr Goto Github PK

this would be a handy enhancement for rstudio.

currently large images spread across the page but the mouse click only works within the surrounding div.

Might need to proportional resize image for display but apply scaled georeferencing to original.

currently all calculations done in leaflet standard epsg:3857

this would likely require the conversion from .pdf to .png or .jpg. Possible method would be:

https://stackoverflow.com/questions/18617270/convert-pdf-to-png-in-r/18617759#18617759

current raster output is:

class       : RasterBrick 
dimensions  : 583, 1006, 586498, 3  (nrow, ncol, ncell, nlayers)
resolution  : 0.3790397, 0.5195278  (x, y)
extent      : -175.9534, 205.3606, -148.4456, 154.4391  (xmin, xmax, ymin, ymax)
coord. ref. : NA 
names       : X0.1, X0.2, X0.3 
min values  :    0,    0,    0 
max values  :  255,  255,  255

need to ensure coord. ref. is specified and preferably user defined

From @mdsumner on November 26, 2018 12:9

I traced this out using affinething - appreciate the shiny example, this could be worked up into a neat application!

library(raster)
r <- brick("inst/shiny/image_click/world.png")

## click southwest, then northwest 
## (I chose the gridline intersections west of SAmerica ,and NULL island)
## note that shiny returns the pixel count from the top, so nrow - y
## these values are reported by the shiny app on screen currently
xy <- rbind(c(x = 194, y = nrow(r) - 416),
c(x = 490, y = nrow(r) - 292))

## those locations are these coordinates, the grid line intersections 
pts <- rbind(c(x = -120, -50), 
             c(x = 0, 0))

rfix  <- setExtent(r, affinething::domath(pts, xy, r = r))
plotRGB(rfix)
maps::map(add = TRUE)
points(pts)

Copied from original issue: mrjoh3/geoflowr#1