# ImMeasures

From MatImage

The imMeasures module provides several functions for measurements on digital images. Most functions are simple wrappers that manage 3D and/or color images, as well as eventual type conversion. Some geometrical measures are provided as well, for description of particles in binary or in label images.

## Contents

### Image exploration

imHistogram - Histogram of 2D/3D grayscale or color images imHistogramDialog - Open a dialog to setup image histogram display options imColorHistogram - Plot 3D histogram of a color image imLineProfile - Evaluate image value along a line segment imEvaluate - Evaluate image value at given position(s)

### Entropy and mutual information

imJointHistogram - Compute joint histogram of two images imEntropy - Compute entropy of an image imJointEntropy - Joint entropy between two images imMutualInformation - Mutual information between two images

### Regions / particle analysis

imCentroid - Centroid of regions in a label image imBoundingBox - Bounding box of a binary or label image imInertiaEllipse - Inertia ellipse of a binary or label image imInertiaEllipsoid - Inertia ellipsoid of a 3D binary image imInscribedCircle - Maximal circle inscribed in a particle imInscribedBall - Maximal ball inscribed in a 3D particle imEnclosingCircle - Minimal enclosing circle of a particle imOrientedBox - Minimum-area oriented bounding box of particles in image imFeretDiameter - Feret diameter of a particle(s) for a given direction(s) imMaxFeretDiameter - Maximum Feret diameter of a binary or label image imConvexity - Convexity of particles in label image imRegionFun - Apply a function to each region of a label image

### Particle moments

imMoment - Compute simple moment(s) of an image imCMoment - Compute centered moment of an image imCSMoment - Compute centered and scaled moment of an image imHuInvariants - Compute Hu's invariant for an image

### Geometrical measures from binary images

perimeter - estimate perimeter of a structure epc - compute Euler-Poincare Characteristic (EPC) of a structure. tpl - compute total projection length specificSurface - implementation of Ohser's algo for surface comput. specificIntMeanCurv - Ohser's Integral of Mean Curvature specificIntMeanCurvDetails - Ohser's Integral of Mean Curvature with details

### General information on images

imSize - Compute the size of an image in [x y z] order is3DImage - Check if an image is 3D isColorImage - Check if an image is a color image imPhysicalExtent - Compute the physical extent of an image imGrayscaleExtent - Grayscale extent of an image imFindLabels - Find unique labels in a label image

### Descriptive statistics on pixel values

imSum - Sum of a grayscale image, or sum of each color component imMean - Mean of a grayscale image, or mean of each color component imStd - Standard deviation of pixel values imVar - Variance of a grayscale image, or of each color component imMin - Minimum value of a grayscale image, or of each color component imMax - Maximum value of a grayscale image, or of each color component imMedian - Median value of a grayscale image, or of each color component imQuantile - Computes value that threshold a given proportion of pixels imMode - Mode of pixel values in an image

### Extract geometric primitives

imFind - Return coordinates of non-zero pixels in an image imRAG - Region adjacency graph of a labeled image imContours - Extract polygonal contours of a binary image imBinaryToGraph - Transform a binary image into a graph structure