« Last post by lammert on October 24, 2021, 09:48:00 AM »
Without knowing the picture and the conversion settings it is difficult to give a definite answer, but your problem is most likely caused by the limited color palette of embroidery colors.
With only about 500 colors, the embroidery thread manufacturers have made choices about which colors to use, and there are very few color choices between black and middle gray. Very dark colors close to black are black-brown, black avocado green and very dark navy blue. These very dark colors are often selected by the algorithm when there is a slight red, green or blue hue over the picture. Even if that hue can't be identified by the naked eye. Technically these colors match better the digital picture, but for the human eye, they may not look natural.
On the light side, there are many more near-whites on the red/yellow/brown side then there are on the green/blue side. This is because thread manufacturers have chosen to prefer a large selection of skin colors above the other colors.
Unfortunately this is a problem we cannot solve, and your picture with very large contrast swings and colors near to the end of the brightness scale might just not be a good fit for a conversion to an embroidery pattern.