The SVG output from this vectorization may be downloaded here. There are a few corners that are slightly rounded in the result but that are sharp in the original, but for the most part the vectorized result matches the original quite well. Load the image by dragging and dropping it onto the application.īy and large, the result is very good.Using Vector Magic Desktop Edition, I vectorize it with the following steps: In cases where a better scanner were available, it might make sense to scan at 300 dpi. In this case, I think it would make the most sense to scan at 150 dpi. Again, such a blurry result should be considered to have a much lower effective resolution. Likewise in the 600 dpi case, where the blurring spans three or four pixels. In either case, the effective resolution of this image is not 300 dpi. It is not clear whether this is due to limitations of the physical sensors or some processing done by the scanner or the scanner software. In the 300 dpi case, the blurring spans two or three pixels, indicating that some blurring has occurred. That pixel should then be some appropriate gray, depending on how far across the pixel the edge actually lay. If the edge is infinitely sharp, then it should only be seen by one pixel in the scanner's sensor. In the 150 dpi case, the blurring at the edge is essentially just one pixel wide. Zooming in on an edge in the image is instructive. The scans themselves are too large to show in-line in this tutorial, but here are the links to the various sizes: 150 DPI, 300 DPI, and 600 DPI. Sure, scanning at 600 dpi, gives you an image of twice the size, but it is also twice as blurry. As I indicated in the best practices section above, I concluded that it doesn't really make any sense to scan at higher than 300 dpi. In this section, I will describe my findings. Then, I scanned this using a consumer-grade Canon scanner at three resolutions: 150, 300, and 600 dpi. This resulted in a very crisp, clean print - out of the image, filling a 6 inch square. Next, I printed that file using a high-quality laser printer. Here is a rasterized bitmap version of that file: You can download the SVG version of this here. I found an interesting public-domain vector image of a Celtic knot design. In order to illustrate some of the characteristics of scans, I've done a little experiment. You may crop it to the correct size, but more advanced operations typically only serve to remove information from the scan.Ī closer look at scan quality at different resolutions I would typically choose 150 dpi for most scanning, especially if you intend to vectorize the resulting bitmap.ĭo not scale, filter, or otherwise alter the raw scan before vectorizing. For typical consumer-grade scanners, it rarely makes sense to scan at higher than 300 dpi, as scanners are mostly hallucinating any details at a higher resolution anyway. Make sure your scan bed is clean and dust free. While such features do enhance certain aspects of the scanned result from an aesthetic perspective, they only make it harder to vectorize. Turn off any unsharp mask or other contrast or edge-enhancing features.
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