Region Thresholding ....

[joslin]

Hi,

I have been looking around and I cannot find a function which would give you the min/max X/Y values for an image (one or three channel) for a specific set of colour values (in my case one, but a threshold might be nice) .... the closest I have come is min/max values, but of course they will give the X/Y but not necessarily the min and max in the image.

Would be useful, anyone know?

[Vladimir_Dudnik]

Hi,

may be you can use min/max after ippiLUT function?

Regards,

Vladimir

[joslin]

Hi,

But this would give me the lowest value's position in terms of X/Y, but it would not give me the limits of that region adjusted by LUT.

Perhaps I was not clear (or did not understand your response), I am looking for the X/Y limits (2D bounding box) for a specific set of pixels. In my case I am using a single channel, and a single instensity value and need to found the bounding box of those pixels of that value (which is ideal for tracking regions).

Any further ideas ????

Many thanks, Chris.

[joslin]

Hi,

Thanks for the code, but I already have this. I am looking for something faster in IPP (it's purpose no?) ...

Seems like a basic function that one would use in Image processing, but missing in IPP. Well I shall submita suggestion then.

Many thanks to all,

Chris.

[seiji-torigoe]

My English is not good.

I might not understand your processing.

However, is it ippiFloodFill that you are looking for?

Or, is it ippsMinMaxIndx?

Message Edited by Seiji-Torigoe on 11-05-2004 02:29 AM

[joslin]

Hi,

Really I need to get better at explaining :)

What I am doing is searching a 2D region for a specific colour match (currently I am using GT/LT functions, but LUT is also acceptable, although function wise no fewer calls). With a specific colour match I enter this pixel entry into an identically sized 2D, single channel, plane which I turn a pixel a specific colour (a value from 0 - 255, but always the same).

I then post-process and remove some noise, and end up with a single patch of this specific "colour".

In order to determine the region/size of the colour I need to search for its limits (i.e. (X, YMin), (X, YMax), (XMin, Y), (XMax, Y)) wherebyX, YMinequates toYMin is wherethelowest pixel Index is for this specific colour, and X is the X coordinate at this position ...at the moment I am searching in pretty much the same way as one of the previous postings (two up from this one) ... but it's slow and as IPP is basically a fast implementation of many useful function ... it seems tome that thereshould be something like this .... but there isn't - unfortunately.

Anyway, if no-one has any solutions, I shall post this as a suggestion to the next edition of IPP.

All the best, Chris.