Calculate area of an anomalous object

[DavidJCrawford]

Hi,

I just tried your image in vision assistant and got two areas using particle analysis. One is 3078 pixels and the other is 2817.

My assumption is that you have Vision module installed on your PC.

Have you tried it?

David

[adobefree@gmail.com]

i used to believe this area euqals to the bounding box area , not the polygon area , maybe i was wrong

[DavidJCrawford]

It doesn't seem to. I worked out the height and width using the reported bounding box to get the bounding area. They are not the same result.

Somebody had suggested a 1-bit pixmap. Use that to prove the reported area of the particles. Convert the image into that pixmap and count the total number of TRUEs. It should equal the sum of the two figures I supplied to you.

Try it and let us know what you find.

cheers

David

[adobefree@gmail.com]

following is my results

1 Vision Assistant :

threshold minvalue  object1(area)  object2(area)

128                        3078                 2817

2  threshold .vi+ convert imgae to array + count 255 pixel

threshold minvalue  object1(area)  object2(area)

128                        3078                 2817

           finally , i found it was not even a question

[ben64]

I converted the image to a pixmap and counted the number of white pixels. I found that the image contains 7144 white pixels and a total of 360960 pixels. So the white pixels area is 1.97917% of the image. See the attached VI (LV 2009).

Ben