Table 2.

Descriptors of Mitochondrial Morphofunction for Tetramethylrhodamine

No.a	Descriptor	Symbol	Definition/meaning of descriptorb
1	Aspect ratio	AR	Ratio between major axis and minor axis of an ellipse equivalent to object: measure of mitochondrial length.
2	Area/Box	Ab	Ratio between the area of an object and the area of its bounding box.
3	Box XonY	Bxy	Ratio between the width and the height of an object's bounding box.
4	Density mean	Dm	Average intensity of object (grayvalue): average mitochondrial intensity of TMRM signal.
5	Axis minor	Axm	Length of minor axis of ellipse with same moments of order 1 and 2 as object (pixels).
6	Diameter maximum	Dimax	Length of the longest line joining two points of the object's outline and passing through the object's centroid (pixels).
7	Diameter minimum	Dimin	Length of the shortest line joining two points of the object's outline and passing through the object's centroid (pixels).
8	Diameter mean	Dim	Average length of diameters measured at 2-degree intervals and passing through the object's centroid.
9	Radius maximum	Rmax	Minimum distance between the object's centroid and outline (pixels).
10	Radius minimum	Rmin	Maximum distance between the object's centroid and outline (pixels).
11	Perimeter ellipse	P1	The perimeter of the ellipse surrounding the outline of each object (pixels).
12	Radius ratio	Rr	Ratio between Rmax and Rmin.
13	Roundness	F	Perimeter2/(4*π*Area; or Formfactor or F): measure of mitochondrial length and degree of branching.
14	Length	Le	Feret diameter (caliper length) along the major axis of the object (pixels).
15	Width	Wi	Feret diameter (caliper length) along the minor axis of the object (pixels).
16	Perimeter2	P2	Chain code length of the outline (pixels).
17	IOD	IOD	Integrated optical density of all objects (grayvalue): sum of all mitochondrial TMRM intensity values.
18	Perimeter convex	Pc	Perimeter of the convex outline of the object (pixels).
19	Perimeter	P3	Length of the object's outline (pixels).
20	Perimeter ratio	Pr	Ratio of convex perimeter to perimeter.
21	Area polygon	Ap	Area included in the polygon defining the object's outline (same polygon as used for perimeter).
22	Count	Cou	Size-weighted object “count” (number of objects).
23	Box width	Bw	Width of the object's bounding box (pixels).
24	Box height	Bh	Height of the object's bounding box (pixels).
25	Feret minimum	Fmin	Smallest feret (caliper) length (pixels).
26	Feret maximum	Fmax	Longest feret (caliper) length (pixels).
27	Feret mean	Fm	Average feret (caliper) length (pixels).
28	Density minimum	Dmin	Minimum density inside object (grayvalue).
29	Density maximum	Dmax	Maximum density inside object (grayvalue).
30	Density standard deviation	Dstdv	Standard deviation of intensity or density inside object (grayvalue).
31	Margination	Ma	Distribution of intensity between the center of an object and the edge of the object.
32	Area	Area	Area of the object (pixels).
33	Center X	CX	X coordinate of the object's centroid (pixel position).
34	Center Y	CY	Y coordinate of the object's centroid (pixel position).
35	Angle	Angle	Angle between the major axis of the object and the vertical.
36	Axis (major)	Axmaj	Length of the major axis of the ellipse with the same moments of order 1 and 2 as the object.
37	Fractal dimension	FD	Fractal dimension of the object's outline.
38	Center X (mass)	CmassX	Intensity-weighed centroid X-position (pixel position).
39	Center Y (mass)	CmassY	Intensity-weighed centroid Y-position (pixel position).
40	Heterogeneity	Het	Fraction of pixels that deviate more than a certain range (here 10%) from the average intensity.
41	Density Sum	Dsum	Sum of intensity inside the object (grayvalue).
42	Perimeter3	P4	Corrected chain code perimeter (pixels).

^aAdapted from (30, 147).

^bAdapted from the definitions in the Image Pro Plus software. Whenever the measurement unit is not specified between brackets, it is arbitrary units.

TMRM, tetramethylrhodamine.