Tuesday, 14 October 2008

Scanning and Converting Images to Vectors

Scanning a document into a computer is easy, but converting it to vectors without losing too much detail is difficult.

When you scan an image, it is a file type that memorizes the image with pixels. The word 'Pixel' is a contraction of the words 'Picture' and 'Element', two words that perfectly summarize both what a pixel is and what they are used create. It is the smallest piece of information in an image and is typically a sample of the original image, so that when many are grouped together they create a clearer image of said image. It is a very clever system, but it is also quite a dated system. This is only a very concise description of what pixels are, but I am not writing this blog about pixels, but rather about Input and more specifically conversion of said Input.

Vectors differ from Pixels greatly. Vector is a word we might more often associate with coordinates and algebra rather than computers and interesting enough, that is exactly what they are - coordinates and math for the computer. Vectors use Geometric shapes, lines and points to equate graphics, rather than samples of the original image. By doing this, not only can the computer calculate them faster (Because computers are built around binary, they are made to calculate data and numbers - that is what they were originally built to do) but they actually look better - there is no resolution distortion or loss of image quality. 'Better' isn't a great term: digital might be better. The images look better on computer screens, they are brighter and more alive but they are also significantly less human.

OK, now that we are clear on what the difference between Pixels & Vectors are, we can begin working. I will be creating a very short animation and using many, many different mediums to transfer that image to the computer. I will then be comparing the results, for clarity and future usage. For instance, will an animation turn out better if I scan images in, convert them and then use them in an animation or will the results be better if I just draw straight into a computer. I will be looking at many different mediums including pencil, clay, photographs, scanning and so forth. I will use the same piece of animation in all of these different mediums so that the difference in the results is crystal clear.

As an example of the difference in results that I expect, I will do a starting test by scanning in two different drawings of the same image and converting it to vectors, before comparing the results.

The first image was a very rough drawing in pencil. The second image is a traced version of the drawing in a darker, clearer pencil - this would be the drawing animation studios would use to scan in, so I expect the results to favor the traced drawing.

Both images are below scanned at 300 dpi. Can you tell which one is traced and which one is rough?



Already we see the higher image quality in the lined drawing. The paper that I used for tracing the image is professional 40grm animation paper - obviously that has made the difference. I will now convert the images in vectors and we can compare the difference in results.




As you can see from above, neither drawing transferred to vectors very well. There are probably just too many lines in this complicated image for the program to deal with. I will look into different programs and see if I can better results for when I actually start scanning in the scenes. I think this is going to be quite a fun investigation in using different methods of animation and it is also going to be very helpful in the future for knowing the ins-and-outs and difficulties of each method of animation.

Although, this was the not the result I was expecting, with a bit of work with Flash, you could probably get tighter vectors and better results - but this was mainly just an example of the kind of thing I will be doing throughout my T&P project. I will animate the scene I will be shooting, then I will begin doing the same animation in a series of mediums recording the difficulties and advantages to all the methods and the time spent and everything else.

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