转发：some question about h_minma (need a paremeter, and can run faster)
Sorry, May be I had send one, But I am not sure if I send suceessfully, because of the attachment is too large, so I send again, with a jpg format. Hi every one: As I mentioned befor, In the official example, use watershed to segment two circle, In this example, use pick_local_max to find the seed. But When I try on other binary images, there always are two local_max nearby, then the segment be too trivial. And I use the h_maxma and h_minma, I have some trouble: 1. when a region has more than one min value(same but not nearby), the result will mark them all. (I want to use them as seed to watershed, So I need any one, else the region will be broken, can we add a parameter to control?)2. h_minma run too slowly, (what more, the watershed run more slowly... so my program crashed! I had heard Juan will improve it in the next version) So I wrote h_minma/maxma and watershed myself (as a sub package of my project imagepy). My watershed now only support 2D, But the h_minma now is OK, works on nd. I had test one image: scikit-image's h_minma runs in 15s, and mine runs in 0.3s, 45times. I will attach my code and test image. If any one can have a look, and improve the h_minma function? I will write a issue on github soon. YXDragon
Hi, YXDragon On Fri, Sep 8, 2017, at 21:25, imagepy@sina.com wrote:
So I wrote h_minma/maxma and watershed myself (as a sub package of my project imagepy). My watershed now only support 2D, But the h_minma now is OK, works on nd. I had test one image:> scikit-image's h_minma runs in 15s, and mine runs in 0.3s, 45times. I tested on my machine and can confirm the slowness. Would you be willing to help profile the code, to find out why it is so slow? Best regards Stéfan
1. when a region has more than one min value(same but not nearby),
Hello, just to comment on your remarks. the result will mark them all. (I want to use them as seed to watershed, So I need any one, else the region will be broken, can we add a parameter to control?) I think there is a problem in the naming of the operator; I will open an issue on this. But this can be easily fixed. There is no parameter to be added.
2. h_minma run too slowly, (what more, the watershed run more slowly... so my program crashed! I had heard Juan will improve it in the next version) h_minima are based on the grey-scale reconstruction; so I guess that if h_minima is too slow, the reconstruction operator and all derived operators will have the same issue.
Best, Thomas. On 9/9/17 6:25 AM, imagepy@sina.com wrote:
Sorry, May be I had send one, But I am not sure if I send suceessfully, because of the attachment is too large, so I send again, with a jpg format.
Hi every one: As I mentioned befor, In the official example, use watershed to segment two circle, In this example, use pick_local_max to find the seed. But When I try on other binary images, there always are two local_max nearby, then the segment be too trivial. And I use the h_maxma and h_minma, I have some trouble:
1. when a region has more than one min value(same but not nearby), the result will mark them all. (I want to use them as seed to watershed, So I need any one, else the region will be broken, can we add a parameter to control?) 2. h_minma run too slowly, (what more, the watershed run more slowly... so my program crashed! I had heard Juan will improve it in the next version)
So I wrote h_minma/maxma and watershed myself (as a sub package of my project imagepy). My watershed now only support 2D, But the h_minma now is OK, works on nd. I had test one image: scikit-image's h_minma runs in 15s, and mine runs in 0.3s, 45times.
I will attach my code and test image. If any one can have a look, and improve the h_minma function? I will write a issue on github soon.
YXDragon
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participants (3)
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imagepy＠sina.com -
Stefan van der Walt -
Thomas Walter