I use a "snipping tool" program and I open my pic, snip the pic and then dump it into microsoft paint and then save as a JPEG.
Below file is 4,296KB in size in original format. Thru what I described above it is reduced to 183KB. You may also be exceeding the physical pixel size as well, so yes you may have to re-size to fit within whatever the parameters are.
View attachment 2860