| 1 | Houghlines in java.
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| 2 | Houghlines does detect white lines. Use binary_inv to show with houghlineTest.png
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| 3 |
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| 4 | OTSU threshold gives best black and white response
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| 5 |
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| 6 | Would it be useful to process what lines have been detected?
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| 7 | As in, filter out every line detected except for horizontal lines?
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| 8 |
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| 9 | BINARYINV seems to be result in a better looking image than canny for sheet music
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| 10 |
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| 11 | In houghlines parameters, having resoluation of 1 degree and 1 pixel makes sense. Would allow for sheet music image to be at any orientation.
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| 12 | Threshold would ideally need to vary dependant on how much sheet music there is.
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| 13 | Which brings to the table filtering. Having a good filter that eliminates noise leaves the sheet music free would be good. The binary inv would be suitable, since houghlines detect white lines.
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| 14 | Need filter to denoize image. OTSU seems to do a good job.
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| 15 |
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| 16 | The threshold would need to be adjusted dependant on how many white pixels there are.
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| 17 | houghlinesP has start and end points. where houghlines does not. Which is why houghlinesP performs better on a set of images becuz of the end points rather than just "a line must meet a certain threshold at that coordinate for it to be registered"
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| 18 | Houghlines in order to be effetive must be scaled to suit the image.
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| 19 |
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| 20 | HoughlinesP contains this:
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| 21 | minLinLength: The minimum number of points that can form a line. Lines with less than this number of points are disregarded.
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| 22 | maxLineGap: The maximum gap between two points to be considered in the same line.
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| 23 |
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| 24 | ____ _____ ______ ______
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| 25 |
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| 26 | HoughlinesP can calculate on a local scale, comaparing the distance between just the gap in the line.
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| 27 | Houghlines only calculates on the lines scale, checking the whole lines point count(attenuator?) reaching over the threshold.
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| 28 |
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| 29 | This means houghlinesP can scale better and allow for more accurate results
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| 30 |
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| 31 |
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| 32 | The mathRound does not make difference
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| 33 |
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| 34 | Drawing forloop with cols, seems to be less effective
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| 35 | Even though it does employ same calculations?
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| 36 | https://stackoverflow.com/questions/29493267/how-to-detect-lines-using-houghlines-in-opencv-java
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| 37 |
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| 38 |
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| 39 |
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| 40 | not enough MP records with more than 10 pages
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| 41 |
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