/images/3515684#comment_11074393 shows that old Pony Town map (which other servers use)'s size is 5120x3840 and the current one is 6400x4800. Polyethylene Server's mini-map allows copy image after adding Allow Right-Click - Microsoft Edge Addons, and under x1 zoom, the image is 160x160. This means each block in Pony Town is 32x24, because 5120÷160=32 and 3840÷160=24. Since we know the current one's map size is 6400x4800, and a block's size is 32x24, we could know the current map has 200x200 blocks, because 6400÷32=200 and 4800÷24=200. This means if we set the Pony Town's mini-map as 200x200 and use the smallest zoom, we can get the original mini-map.

I havn't find the way to delete the pins from the webpage yet, so I deleted them manually. Yet on library, a pixel's color cannot be decided, so I guessed it.

~Minimap without pin while unknown spot on library is red~

How I deleted pins manually:

After zooming-in, pixels hidden by pins could be shown. This is the way to know the pixel's colors behind the pin.

First, I have to know which pixels belong to the pin: because the pin uses anti-aliasing function, I shouldn't directly edit the copied image, as some pixels looks like pin pixels but are actually not, and some pixels looks like map pixels but are actually pin pixels. So I zoomed-in the map, copied the image, pasted it into MS Paint, and filled map part around the pin into other colors, and finally made the left part, which is the pin, as monochrome.

~Get minimap's pin's shape~

If I just simply move these shapes onto the copied mini-map image, my workload would be too heavy. Thus, I made Pony Town's mini-map's size as 800x800 (so each spot's size is 4x4. If the mini-map's size is 700x700, then some spot would be 4x4 and some would be 3x3), then copied the image into MS Paint, then pasted monochrome pin's shape on the pin, then change the 800x800 image into 200x200.

~Know minimap's pin's area~

Then I can change the pin's pixels into the mini-map's pixels by zooming-in and see these pixels. (Yet one pixel on library is still hidden after zooming-in (the maximized total mini-map’s size is 3000x3000), so it's cannot be known. Thus I guessed it through the real library's color. Now the library's roof is covered with snow, so I looked at >>3515684. Yet it cannot be 100% correct. And this way is too slow, so in the future, the way editing the webpage's code to delete the pin on the webpage must be found.)

~Change the pin's pixels into the mini-map's pixels by zooming-in and see these pixels; and the unknown pixel~

Update: The unknown pixel is now known

In “Settings”’ “Minimap” section, for PC's webpage, the default “Icon size” is shown as 1x, but for moblile phone, the number is higher. So I used Inspect (F12), then clicked “Toggle device emulation”, then chose “Dimensions: iPhone 14 Pro Max” (where default “Icon size” is shown as 6x), then set “Settings”’ “Minimap”’s “Icon size” as 1x.

~Make pins small~