Vectorizing images with soft color blends & continuous tones
If the image that you need vectorized has a multitude of colors or color blends you may need to decide the best way for vectorization. Color blends and soft color gradients are achieved by the use of a multitude of color pixels and since vectors do not use pixels the vectorized file will look slightly different.
Vector programs do offer tools for adding color blends as smooth as any raster program, but these effects are RASTER effects and are unacceptable for processes that require 100% vector art.
If the image quality allows, a raster image with color blends may be vectorized with the aid of automated software. The appearance of the image can be preserved but this type of vectorization may render the image unsuitable for certain processes. The vectored image will have a multitude of colored objects and may not be suitable for spot color separation, vinyl cut signs, engraving and any other process that is guided by the "wireframe" or "outline" of the vector file. Suitable for web use, CMYK or digital processes only.
Manual drawing with a pen tool - node by node - is often necessary to produce the desired results. This is more time consuming than automated tracing therefore more costly. Gradients & shadows effects allow a softer blend of colors but vector files with raster effects are not suitable for all processes.
Manual drawing with a pen tool - node by node - with NO gradient effects produces a file suitable for all processes. 100% vector art with no raster effects is required by process that are guided by the vector outline such as engraving, vinyl cut signs, and some specialty printers. The original appearance of the image will most likely change, the new vector image will not have the soft gradation from one color to another, instead it will have a clear distinction between each color. See more samples
A simplified version using a very limited amount of colors for easy spot color separation. 100% vector art suitable for all processes. See more samples
Matching colors when vectorizing can be a problem but only if the original image is a full color image and the vector image needs to be created using a limited amount of colors. Although the original image below may seem to be a three color image; olive, gray and black, it is in fact a full color image with hundreds of different color pixels. The embossed look, highlights, shadows and color blends are accomplished by using a multitude of different color pixels from light to dark.
The same image using only 3 colors - olive, gray and black - will look considerably different: