1. In a digital medium environment to enhance picture vectorization by facilitating conversion of raster images to vector images based on spatially-localized user control, a method implemented by a computing device, the method comprising: displaying a raster image corresponding to a picture having multiple semantic elements, the raster image including multiple image features; segmenting the raster image into multiple segments, each segment of the multiple segments based on at least one image feature of the multiple image features, the multiple image features serving as a proxy for the multiple semantic elements of the picture; presenting a user interface feature to provide localized control of a vectorization of the picture, the localized control pertaining to a portion of the raster image; detecting a user control signal indicative of the portion of the raster image for which a localized vectorization characteristic is to be adjusted; producing a vector image corresponding to at least part of the picture based on the multiple segments and an adjusted localized vectorization characteristic; and displaying the vector image.