|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
Some Questions about Hough Transforms...
How can I determine the length of the line that the hough transform
detects? What goes on with aliased lines... for example.. X X X X X X X Is this three vertical lines or is it one line? I seem to remember there being a modified hough transform that would tell you were the line started and ended.. anyone else seen that paper? If so.. Got a link? |
#2
|
|||
|
|||
Some Questions about Hough Transforms...
On Apr 17, 7:26*am, SpreadTooThin wrote:
How can I determine the length of the line that the hough transform detects? What goes on with aliased lines... for example.. X X * X * X * X * * X * * X Is this three vertical lines or is it one line? I seem to remember there being a modified hough transform that would tell you were the line started and ended.. anyone else seen that paper? If so.. Got a link? In my opinion, whether they are one line or not is depend on the bin you use in hough transform parameter space. and after hough transfrom, the bin where peak lying holds the length(in pixel) and line parameters (e.g. K and B in y = K*x+ B). With these parameters, the ending of line is possible to be found by some discussion. Best Regards, lomas |
#3
|
|||
|
|||
Some Questions about Hough Transforms...
Is this three vertical lines or is it one line?
That will depend on the resolution of your accumulator. Determining the length of your line: if the input to the hough transform is a binary image, then the length of any possible line could be considered to be the value in the corresponding accumulator bin. However, I would not recommend using this as the length. I think that the HT is good for getting general positions of lines, but if you want length/position of lines you need to then use other methods as well. |
#4
|
|||
|
|||
Some Questions about Hough Transforms...
On Apr 18, 5:12*am, JS wrote:
Is this three vertical lines or is it one line? That will depend on the resolution of your accumulator. And this is really the problem I'm facing.. How do I determine the size of the accumulator? I can find the maximum peak easily, but what about other peaks in the image... How can I go about finding those? I'm wondering if I should find a peak and then use the neighbors as a weighted sum to get the actual R Theta... Make sence? Determining the length of your line: if the input to the hough transform is a binary image, then the length of any possible line could be considered to be the value in the corresponding accumulator bin. *However, I would not recommend using this as the length. *I think that the HT is good for getting general positions of lines, but if you want length/position of lines you need to then use other methods as well. |
#5
|
|||
|
|||
Some Questions about Hough Transforms...
SpreadTooThin a écrit :
How can I determine the length of the line that the hough transform detects? What goes on with aliased lines... for example.. X X X X X X X Is this three vertical lines or is it one line? I seem to remember there being a modified hough transform that would tell you were the line started and ended.. anyone else seen that paper? If so.. Got a link? You can increase the dimension of your Hough transform to make it 4 dimensions instead of 2 (for example the 4 dimensions are the x1,y1,x2,y2) and find your maximum in this 4 dimensional space. You will directly get your x1,y1,x2,y2 and the corresponding length. Otherwise, I don't really know how to get the length in the usual Hough transform since it only encodes directions. -- Nicolas Bonneel http://www.bonneel.com |
#6
|
|||
|
|||
Some Questions about Hough Transforms...
How can I determine the length of the line that the hough transform
detects? MATLAB has the houghlines function to get the length. I have tried it is very useful. You must provide two parameters : 'FillGap' and 'MinLength' |
#7
|
|||
|
|||
Some Questions about Hough Transforms...
On May 6, 7:18*am, Norberto Goussies wrote:
How can I determine the length of the line that the hough transform detects? MATLAB has the houghlines function to get the length. I have tried it is very useful. You must provide two parameters : 'FillGap' and 'MinLength' Oddly enough thats exactly what I did in my application. Cool. |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
EINSTEIN 1905 DERIVATION OF LORENTZ TRANSFORMS | Pentcho Valev | Astronomy Misc | 7 | September 30th 07 05:48 PM |
More Questions | Macro | Amateur Astronomy | 3 | September 13th 07 11:26 PM |
Lorentz transforms physical incoherence | [email protected] | Astronomy Misc | 223 | June 24th 05 12:48 AM |
ISS O2 questions? | JJR2 | Space Station | 12 | May 22nd 05 12:45 AM |
A Few Questions: | Bob Carlson | Astronomy Misc | 4 | May 13th 04 04:37 PM |