Morphology . blobber | Mlx Home

Morphological measurements available with the blob widget top

  1. Blob Info Window:
    1. Area
    2. Maximum diameter
    3. perimeter
    4. Centroid
    5. Weighted Centroid
  2. Blob Stats Window (30 Jan 97 - These need checking.)
    1. Total intensity
    2. Intensity range

Area top

The area is the number of pixels in an object. Strictly speaking, this is the number of contiguous pixels forming a group. The pixels chosen depend on the threshold setting - it is possible, even likely, that the pixels in the group do not exactly correspond to the desired object.

Maximum diameter top

Maximum Feret Diameter, or maximum caliper diameter. Calculated by an algorithm that traverses the perimeter of the object, searching for the pixels on the diameter that are the farthest apart.

perimeter top

Length of the perimeter in pixels. Calculated as the sum of the lengths of the line segments connecting the centers of the OUTSIDE edges of the outermost pixels of a group. The outermost pixels are those that touch the background along at least one edge. Diagonally spaced edge pixels are separated by (sqrt 2). This perimeter measure is less than that calculated by tracing the outside edges of the pixels (it cuts off the corners along diagonal lines) and greater than the edge pixel count. I think it is a reasonable measure.

Centroid top

(x,y) coordinates of the center of mass of the pixel group (or 'blob').

Weighted Centroid top

Same as centroid, except that the coordinate of each pixel is weighted by the pixel intensity, when 'averaged into' the center of mass calculation.


Electron Microscope automation, Microanalysis Group, NIST top

Definitions of morphology terms from VAX Lispix EM automation particle analyzer. These will be implemented into macLispix as required.

  1. SPECTRUM NAME Q8531_001_01_01 Microanalysis group standard name format - run_image_particle_spectrum
  2. PERIMETER 103 count of edge pixels. One approximation. Betters ones when blobber on Mac is used
  3. DMAP_MAX_CENTER (166 401) x,y image coordinates of 'fattest' part of particle
  4. DMAP_MAX_RADIUS 6 radius in pixels of largest circle to fit inside particle
  5. FERET_MIN 13.75681 minimum caliper diameter in pixels
  6. FERET_MAX 25.0 maximum caliper diameter in pixels
  7. A_W_L_I 8.6 length in pixels of axis of least inertia (long axis). Weighed by intensity.
  8. A_L_I 7.9 length in pixels of axis of least inertia (long axis). Uniform weights. (not wtd)
  9. C_MASS (168.2862 401.9304) x,y in pixels of center of mass - weighted by intensity.
  10. ABS_DEV 293.5 version of sigma - average of absolute deviation of pixel brightness from average
  11. R_SIGMA 0.2 relative standard deviation of pixel brightnesses
  12. SIGMA 356.0 standard deviation of pixel brightness
  13. AV_V 1537.78 average pixel brightness or intensity
  14. N_V 984 minimum pixel intensity
  15. L_N_V (177 406) X,Y in pixels of first pixel with min value, scan order
  16. L_X_V (168 400) X,Y in pixels of first pixel with max value, scan order
  17. X_V 2643 maximum pixel intensity
  18. BDR (155 395 180 410) x1, y1, x2, y2 lower left, upper right corners of bounding rectangle
  19. AREA 249 number of pixels in particle
  20. INDEX 91 (internal use: fiducial number or label of particle)
  21. PARTICLE 1 (internal use: another label for the particle. I think.)

CUP_C_AFTER_IMG 710.0 sample of an image parameter. Cup current after image was scanned.

NIH Image parameters