Calculating intercepts using Grid Overlay
How do I count the number of points that intercept with tissue (say the tumor.tif demo image)? I know how to create the grid of points, but need to know the procedure of how to combine the grid with an image so that the intercept points can be counted.
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Best Answers
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The workflow depends on what you actually want to measure. A simplified advice is: create mask of the grid, mask of the image, use AND operation between 2 masks and count the number of bright pixels using Histogram or Count/Size.
If you want to measure grain size and count the number of intercepts with grain boundaries, then you can use another method: add grid to Features Manager and then apply to the image as "Line Profile". You can define edge detectors (Peak or Valley), which will give you total number of intercepts.
If you just want to measure tissue area, you can do it directly using Count/Size.
Yuri
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DCIMAGING --
As YURI mentioned, there are several ways to attack your challenge.
I have illustrated one where:
A = SAMPLE IMAGE with DARK SPOTS OF INTEREST
B = GRID of 19 x 19 (361) CIRCLES
C = MASK of DARK OBJECTS in B
D = MASK of GRID from B (this took two steps to make the CIRCLES be COMPLETELY FILLED)
E = C * .33
F = D * .66
G = E + F (where 0 = black in C and D, 84 = from C, 168 from D, > 168 from C and D)
H = SCREEN CAPTURE with
G + THRESHOLD from 128 to 255
and COUNT
and MEASURE REGION INTENSITY
and SINGLE CLASSIFICATION run on REGION INTENSITY
(CLASS 1 = BLUE = DARKER = NO or LESS OVERLAP = 304 / 361 = 84%)
(CLASS 2 = RED = BRIGHTER = MORE or TOTAL OVERLAP = 57 / 361 = 16%)
I = SCREEN CAPTURE of same analysis done on a 4 x 4 grid of G resulting in
(CLASS 1 = BLUE = DARKER = NO or LESS OVERLAP = 12 / 16 = 75%)
(CLASS 2 = RED = BRIGHTER = MORE or TOTAL OVERLAP = 4 / 16 = 25%)
I have attached TIF IMAGES for A through I and JPG IMAGES for H and I.
Note CIRCLES in the 1st and 3rd COLs of the 4th ROW of the 4 x 4 GRID. These have overlap between C and D but not enough to be classified as CLASS 2.
I hope this helps.
-- MATT
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Matthew M. Batchelor
President and Applications Engineer
Alces Imaging and Automation, LLC
2906 Blue Wind Court
Houston, TX 77084
Office: 281-646-7477
Cell: 713-818-7832
Fax: 281-599-8780
E-Mail: matthew.batchelor@alces.us
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