Vectorization

As opposed to a photographic image that is pixelized or rastorized (made up of dots) a vector is solid line art.  An advantage of line art is that it can be blown up to any size with no degradation of sharpness.

This illustration of a carnival ride for children began with a photo from a series “SUNSET ON  SMALL TOWN CARNIVAL”.  Small town carnivals are rapidly disappearing. Whenever possible I like to document this vanishing icon of the Twentieth Century American landscape.

The image was captured on a Sony camera as a TIFF.  In PS (PhotoShop), it was first converted to a PSD (PhotoShop format).  I increased the saturation.  I saved the image and opened it in AI (Adobe Illustrator).  I used auto trace to average out the colors, but this also created white gaps and undesirable patterns.  To get a good trace, this operation required about 200 colors and a high sampling rate which created an enormous file size.

Colorized and converted to vector

So I rastorized the image and returned to PS for serious tracing.  I up sized the image by a factor of 2.  Then using single colors, I colorized areas with similar tones and also eliminated any ‘white gaps’.  I also had fun changing all the faces and adding color anywhere that felt good.  I darkened some areas and highlighted others.  When I was pleased, I reopened the image in AI.

Again I used auto trace, but this time I played with the sampling rate and number of colors— reducing them to just above the degradation: approximately 40 colors and sampling rate below 100.  The net effect was a significant reduction in file size without losing the detail.

I needed to return to PS with the image to create a JPG and a PNG.  While ‘Super Truck’ can be purchased from an on line gallery as an AI, the galleries all display images as JPGs or PNGs.  Normally, up sizing an image is not allowed (this one began at 72 dpi).  But because I’m working from a vector (with no loss of resolution at any size), when converting back to a rastored image, I can make the dpi whatever I want.  So I create a resolution that is near the maximum megapixels accepted by a gallery (different galleries have different limits).

View Larger Image