Execute Filter-Blur-Special Blur, and the special blur dialog box pops up. Set the quality to high, set the mode to edge first, and adjust the radius value. The picture size is different, and the value is different. Adjust it according to your own picture size, but don't adjust it too much, otherwise the lines will not be clear. Set a threshold, the greater the value, the fewer the number of rows. Click OK to see the effect in the preview box. The shortcut key Ctrl+I is reversed, and the line conversion is completed. Next, use the optional color to turn the line into blue. I wish you success!