[HN Gopher] Computer vision and embroidery
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       Computer vision and embroidery
        
       Author : healeycodes
       Score  : 56 points
       Date   : 2021-04-07 11:01 UTC (1 days ago)
        
 (HTM) web link (healeycodes.com)
 (TXT) w3m dump (healeycodes.com)
        
       | healeycodes wrote:
       | I welcome any improvements to my naive exploration in this
       | article!
       | 
       | I've received two emails from readers:
       | 
       | - One suggested converting RGB to a color space that better
       | matches human visual perception, like CIELAB.
       | 
       | - Another suggested compressing the color space by using K-means
       | clustering (by guessing K as the number of threads)
        
         | harperlee wrote:
         | Is that a good idea? I don't do embroidery but I'd guess people
         | mix threads of different colour in the same area to merge them.
         | As long as the image is original you can discard those areas as
         | false positives instead of new colours; if you compress the
         | image, that subtlety per thread is lost.
        
         | pfortuny wrote:
         | Why not use Cannyedge detection for edge detection? It should
         | work pretty well once you have a greyscale image, and then
         | circle detection as you already do.
        
         | solarmist wrote:
         | What are DMC threads? I tried to read the article, but without
         | knowing that I don't really get anything.
        
           | healeycodes wrote:
           | They are the colored threads that you stitch with. DMC is a
           | brand but it's also the colloquial term for the fixed set of
           | colors that are commonly used and sold.
           | 
           | I'll see if I can make that clearer -- thanks.
        
             | sleepybrett wrote:
             | So pantone but for dyed fiber instead of inks on paper...
        
         | Animats wrote:
         | A color reference would help. Stitch something with standard
         | thread samples and use that for comparison.
        
       | kevin_thibedeau wrote:
       | > I don't account for lighting conditions (how would you do
       | this?)
       | 
       | I'd start by shooting against a white background with full
       | spectrum lighting. Then you can compensate for the camera
       | processing to get roughly calibrated brightness.
        
         | spullara wrote:
         | He can probably just adjust the white balance of the photo
         | until the most colors match the threads with highest
         | confidence.
        
         | mhb wrote:
         | It sounds like he's using photos others have posted. So no
         | access to the lighting.
        
       | aidionidis wrote:
       | This is absolute genius, love it! As a full time java dev, I
       | would really like to start doing some embroidery as a anti-stress
       | strategy. (ugh, I cant even talk without emmbeding at least one
       | desing pattern into my words)
        
         | jalk wrote:
         | I hope you succeed - all my attempts at similar activities,
         | just brings me into "how can this be automated" mode
        
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