Image quality ia poor after saving

[Agucha1986]

Hi, I am using Leaflet to plot raster data, and everything looks good until I save the maps as PNG or any other format.

I use ESRI as the provider.

This is the code I used to save my maps as images.

saveWidget(m, file = "path.html")
mapshot(m, file = "path.png",
remove_controls = c("zoomControl"), vwidth = 700, vheight = 500)

Is that an issue with the package or is there a way to maintain/increase the resolution/quality of the image while saving the map?

Thank,
A

[tim-salabim]

Hi, not sure how to help. Do you have a reproducible example?

[Agucha1986]

Hi Tim, I am sorry for the late reply. I've attached an example using free and publicly available boundaries for NSW in Australia. The boundaries are here (too large to attach to the email): https://www.abs.gov.au/statistics/standards/australian-statistical-geography-standard-asgs-edition-3/jul2021-jun2026/access-and-downloads/digital-boundary-files LGA - see Non ABS Structures -> Local Government Areas - 2024 - Shapefile Suburbs - see Non ABS Structures -> Suburbs and Localities - 2021 - Shapefile My issue is the loss of image quality, mainly related to the underlying ESRI World Imagery map. It's perfect when seen as HTML but very poor when saved as any other format (png, jpeg), including pdf. Is there a way to save as image with good quality image/somewhat high resolution? I've also attached my map, which I saved as HTML and png, so you can see the difference in image quality. Best regards, Aga

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On Wed, Jan 22, 2025 at 5:50 PM tim-salabim ***@***.***> wrote: Hi, not sure how to help. Do you have a reproducible example? — Reply to this email directly, view it on GitHub <#499 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/BH4CXT4ZAUKU7YEWCWFEUML2L45TZAVCNFSM6AAAAABVTUPC3OVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDMMBWGQZDSMRVG4> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[tim-salabim]

There's nothing attached. I think you need to upload it here, rather than attaching things to the reply email.

[Agucha1986]

Apologies,

I thought it would go through.
Unfortunately, I can't upload the HTML file, which is a good-quality image. You will see when you produce one.

Here is the code I used:

LGA boundaries

NSWLGA <- st_read("path/LGA_2024_AUST_GDA2020.shp") %>% st_transform(7844)
Sydney_LGA1 <- NSWLGA %>% filter(LGA_NAME24 %in% c("Sydney"))
Sydney_LGA <- Sydney_LGA1 %>% st_transform(7844)
S_LGA <- as(Sydney_LGA, 'Spatial')
S_LGA2 <- sf::st_transform(Sydney_LGA, "+proj=longlat +datum=WGS84")

#Suburbs
NSWLGAs <- st_read("path/SAL_2021_AUST_GDA2020.shp")
Sydney_sub <- NSWLGAs %>% filter(SAL_NAME21 %in% c("Alexandria", "Annandale (NSW)", "Barangaroo", "Beaconsfield (NSW)", "Camperdown (NSW)",
"Centennial Park (NSW)", "Chippendale", "Darlinghurst", "Darlington (Sydney - NSW)", "Dawes Point",
"Elizabeth Bay", "Erskineville", "Eveleigh", "Forest Lodge", "Glebe (NSW)",
"Haymarket", "Millers Point", "Moore Park", "Newtown (NSW)", "Paddington (NSW)",
"Potts Point", "Pyrmont", "Redfern", "Rosebery (NSW)", "Rushcutters Bay",
"St Peters (NSW)", "Surry Hills", "Sydney", "The Rocks (Sydney - NSW)", "Ultimo",
"Waterloo (NSW)", "Woolloomooloo", "Zetland"))

S_sub2 <- st_intersection(Sydney_sub, Sydney_LGA1)
S_sub3 <- S_sub2
S_sub3 <- as(S_sub3, "Spatial")

#map
m <- leaflet(data = S_sub3,options = leafletOptions(zoomControl = FALSE,attributionControl=FALSE)) %>%
setView(lng = 151.206832, lat = -33.885704, zoom = 13) %>%
addProviderTiles(providers$Esri.WorldImagery) %>%
addPolygons(data = S_sub3,
color = "yellow",
fill = NA,
opacity = 1,
weight = 1.5,label = ~SAL_NAME21) %>%
addPolygons(data = S_LGA,
color = "white",
fill = NA,
opacity = 1,
weight = 2)

m # Print the map
saveWidget(m, file = "path/suburbs.html")
mapshot(m, file = "path/suburbs.png",remove_controls = c("zoomControl"), vwidth = 550, vheight = 550)

Thanks,

Aga