eudoxos's profile - activity

Find indices of nearest zero pixel after distance transform I have image I with holes (NaNs) and would like to use dista

Find indices of nearest zero pixel after distance transform I have image I with holes (NaNs) and would like to use dista

Find indices of nearest zero pixel after distance transform I have image I with holes (NaNs) and would like to use dista

Segmentation strategy suggestions I would like to find rectangle-shaped objects in images (of size which is approximatel

Thanks. Will this work also if I have only 1 class of texture, and want to find it against anything else? I will just th

I need to find areas with bulk of spherical objects (for further analysis) when the image contains also areas which are not interesting. A typical image looks like this:

I tried texture analysis using Gabor filter, rotating them around, and checking where they match multiple directions (threshold and blur the result, add all of them together, dilate the result to get contiguous area), indicating there are edges in all directions (which will be the case for spheres but not for flat areas, like that one on the right) - this is in one particular direction:

and this is the final result:

It could be made better by tuning various params, but before I go there: I'd like to have suggestions for a better-suited algorithm for this task -- I've been browsing the internet for texture analysis strategies, such as Haralick features, SURF and others, but having no experience with any of those, it is hard to decide which path to pursue. I hope someone might point me to the right direction. The implementation will be in c++/OpenCV. Thanks!

EDIT: The approach must also work on b/w images, not supposing any particular colors, purely by analyzing texture.

Color-based segmentation is indeed ruled out. I added a note to the question.

Algorithm recommendation for texture analysis/segmentation I need to find areas with bulk of spherical objects (for furt

Algorithm recommendation for texture analysis/segmentation I need to find areas with bulk of spherical objects (for furt

I am trying to segment an image with spherical-shaped objects, something like this being the source:

I tried several approaches:

• blur, adaptive thresholding, skeletonization, then connected components analysis, but it is very sensitive to lighting conditions;
• hough circles (with various pre-filters) which gives too much bogus results, reacts to single points and so on;
• distance map (after adaptive threshold) and watershed, with which I did not get very far (perhaps lack of experience).

The adaptive thresholding gives visually nicely separated objects (below shown with superimposed distance map) but I am having hard time to see which way to proceed all way to segmentation.

I am aware I am not using some features of the scene which are known are not exploited by the algorithm, such as

1. all objects are plus minus circular (modulo occlusion);
2. the objects cover the entire scene, i.e. they are packed quite tightly;
3. size range is known (this is used after segmentation to prune the result only for what is meaningful, but this knowledge comes only after segmentation as clean-up, not as improvement of the segmentation itself)

I would be grateful for some ideas on how to move on.

@LBerger please read comments above, addWeighted is not useful, unless you explain better what you mean.

You must give me an example (as I don't understand how you'd do it) or you did not read my reply above. I need weight to

The argument is an image (InputArray), see setTo docs: https://docs.opencv.org/3.4.0/d3/d63/classcv_1_1Mat.html#a0440e2a

@LBerger: that is not equivalent, unless I am missing something. addWeighted takes scalar weights, but I need weight to

@LBerger: that is not equivalent, unless I am missing something. addWeighted takes scalar weights, but I need weight to

@LBerger: that is not equivalent, unless I am missing something. addWeighted takes weights as scalars, but I need weight

blending 3-channel images with setTo and mask: error: checkScalar? Hi, I am trying to blend background image (3-channel)

3.3 on OpenCL 1.1 device I am running OpenCL 3.3 and I'd like to use the AMD Cayman GPU (OpenCL 1.1. Mesa 17.2.2). While

3.3 on OpenCL 1.1 device I am running OpenCL 3.3 and I'd like to use the AMD Cayman GPU (OpenCL 1.1. Mesa 17.2.2). While

I was thinking along depth edges already, using 3 flashes (RGB), but that is not possible at the moment. For the record,

This is what I already did (connected components after skeletonization) and the result is sometimes good but mostly terr

Segmenting bulk of spherical objects I am trying to segment an image with spherical-shaped objects, something like this