You can create designs in vector format, but for knitting, we (finally) need a pixel based graphic.
Vectors look smooth and clear at any size, but vectors have no pixel, and we need pixel for knitting.
The color of a pixel in the design has the information which color the stitch in the knitwear will have.
Step 1 is to make a pixel image out of your vector design. This is usually done when you save / export from you design software as e.g. PNG file.
This flake below was a vector, now it is a pixel image. Yet, the flake cannot be knitted, it still has 250 colors, mainly greyscales along the edges.And it is still too large.
Step 2 is color reduction and resizing. We have added a light blue border so you see how a third color looks in this.
Now this looks pixeled and low quality, but only this way it can be knitted.
It has to fit the knitting grid and size. You cannot beat that grid by making a "better" vector or blowing up the resolution of the pixel file when exporting it.
From left to right, the flake is scaled down. On the right, there are not enough pixel / stitches to display it, it cannot be recognised as flake anymore.
The second and third flake are ok, but they are not perfectly symmetrical. Even if the initial vector was "perfect", this will not lead automatically to a perfect pixel image, depending on size and level of detail. No half pixel or half stitches can be knitted. When going very small, one or two pixel can make a difference there. Manual pixel editing is needed then.