as mentioned above, Here's a link to Weatherfax plugin for open cpn
the kap made and check to make sure it does exist on your hdd .
not sure how big an image it'll take but your original image should be not much bigger than 4500 pixels across the top 3800 is better yet.
pngs are the best format, jpgs are lossy so work with pngs(256 colours) and convert to jpgs at the very last if you must use them.
Although the raster charts are well scanned
That is really difficult to do! without a huge scanner. Just commenting because any distortion as to "stitching" is a pain.
Including Borders can be difficult for beginners so maybe crop them off for now...
Also every image intended for a mercator
chart must be sized to agree with your images central LATITUDE. That is, a degree of longitude across the top is proportionate to the cosin of latitude. The chart should agree on all four corners. ie it's a perfectly vertical/horizontal rectangle, and it's latitudes and longitudes "agree" at the corners. as in, the two top corners have the same latitude. the right side is on the same longitude etc.
This is a good test of your "scan" and might go some way to explain your problems..
is a good tool and worth getting into. It will even spit out an error telling you how to resize your image to suit the lat/long proportions given it is
simply it's just a matter of upper left corner and lower right corner...
all one line
imgkap[space]-s[space]LNT[space]"yourchartimage.png"[space] youruppercornerlat[space]uppercornerlong[space] lowercornerlat[space]lowercornerlong
then enter/return on the keyboard.
is LowestNormal Tide. but you can do without or substitute the datum found on your chart. s
is for superstition don't ask
add well i see boat_alexandra and I are drinking the same kind of coffee! crossposting haha you win!