Press n or j to go to the next uncovered block, b, p or k for the previous block.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 | import type { PixelDataTypedArray, Point3 } from '../types';
type NeighborhoodStats = {
mean: number;
stdDev: number;
count: number;
};
/**
* Calculates statistical properties (mean, standard deviation) of a neighborhood around a center point in a 3D volume.
* @param scalarData - The array containing voxel intensity values
* @param dimensions - The dimensions of the volume [width, height, depth]
* @param centerIjk - The center point coordinates in IJK space
* @param radius - The radius of the neighborhood to analyze in pixels
* @returns An object containing the mean, standard deviation, and count of voxels in the neighborhood
*/
export function calculateNeighborhoodStats(
scalarData: PixelDataTypedArray,
dimensions: Point3,
centerIjk: Point3,
radius: number
): NeighborhoodStats {
const [width, height, numSlices] = dimensions;
const numPixelsPerSlice = width * height;
let sum = 0;
let sumSq = 0;
let count = 0;
const [cx, cy, cz] = centerIjk.map(Math.round);
for (let z = cz - radius; z <= cz + radius; z++) {
if (z < 0 || z >= numSlices) {
continue;
}
for (let y = cy - radius; y <= cy + radius; y++) {
if (y < 0 || y >= height) {
continue;
}
for (let x = cx - radius; x <= cx + radius; x++) {
if (x < 0 || x >= width) {
continue;
}
const index = z * numPixelsPerSlice + y * width + x;
const value = scalarData[index];
sum += value;
sumSq += value * value;
count++;
}
}
}
if (count === 0) {
const centerIndex = cz * numPixelsPerSlice + cy * width + cx;
if (centerIndex >= 0 && centerIndex < scalarData.length) {
const centerValue = scalarData[centerIndex];
return { mean: centerValue, stdDev: 0, count: 1 };
} else {
return { mean: 0, stdDev: 0, count: 0 }; // Or throw error
}
}
const mean = sum / count;
const variance = sumSq / count - mean * mean;
const stdDev = Math.sqrt(Math.max(0, variance)); // Ensure non-negative variance
return { mean, stdDev, count };
}
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