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Bubble sheets

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Q: Can Pixcavator extract data from Scantron pages, i.e., bubble sheets used for testing, polls, voting, etc.?

Two images of an answer sheet below (the originals were 2.5 MB each with a resolution of 2504x3229 pixels).

BlankPage.jpg FilledPage.jpg

Let's see if we able to capture the bubbles.

BlankPage ss.jpg

FilledPage ss.jpg

Not hard at all. The first image shows how empty bubbles are captured, in the second - only the marked ones, but not crossed. (Here is a company that is doing something very similar [1]. Cost $1K.)

Examples with similar analysis:

Even though the origins of these images are very different, the images themselves are similar to these and the approach to analysis might be identical. There are many examples like this...

The first on the list also provides a prototype program that displays instead of the usual Pixcavator's output table - a table of 0s and 1s for unmarked marked bubbles respectively.

Other image analysis examples