The Octave-forge Image package provides functions for processing images. The package also provides functions for feature extraction, image statistics, spatial and geometric transformations, morphological operations, linear filtering, and much more.

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Detect edges in the given image using various methods.

Convolve 2 dimensional signals using the FFT.

Compute correlation coefficients of images.

Compute the mean value of the 2D image I.

Returns the standard deviation for a 2d real type matrix.

Computes the entropy of an image.

Computes the local entropy in a neighbourhood around each pixel in an image.

Performs quadtree decomposition.

Obtain block values from a quadtree decomposition.

Set block values in a quadtree decomposition.

Calculates the gray-level co-occurrence matrix P of a gray-level image IM.

Perform the Hough transform for lines or circles.

Calculate the straight line Hough transform of a binary image I.

Perform the Hough transform for circles with radius R on the black-and-white image BW.

Compute the gradient magnitude and direction in degrees for an image.

Compute the x and y gradients of an image using various methods.

Produce histogram counts of image I.

Finds local spatial maximas of the given image.

Compute the normalized 2D cross-correlation.

Computes the local intensity range in a neighbourhood around each pixel in an image.

Compute object properties in a binary image.

Computes the local standard deviation in a neighbourhood around each pixel in an image.

Return absolute difference of image or constant to an image.

Add image or constant to an image.

Compute image complement or negative.

Divide image by another image or constant.

Combine images linearly.

Multiply image by another image or constant.

Subtract image or constant to an image.

Uses lookup tables to perform a neighbour operation on binary images.

Estimate total area of objects on the image BW.

Finds the borders of foreground objects in a binary image.

Trace the boundaries of the objects in a binary image.

Find connected objects.

Compute distance transform in binary image.

Calculate the Euler number of a binary image.

Perform a flood-fill operation on the binary image BW1.

Perform the binary hit-miss operation.

Label binary 2 dimensional image.

Label foreground objects in the n-dimensional binary image BW.

Perform morphological operation on binary image.

Find perimeter of objects in binary images.

Select connected regions in a binary image.

Determine the Freeman chain code for a boundary.

Create labelled matrix from bwconncomp structure.

Create a lookup table which can be used by applylut.

Define a colour map which smoothly traverses the given colors.

Convert RGB values to YCbCr.

Convert wavelength in nm into an RGB value set.

Convert YCbCr color space to RGB.

Create montage from multiple images.

Equalize histogram of grayscale image.

Adjust image or colormap values to a specified range.

Add noise to image.

Smooth the given image using several different algorithms.

Two dimensional median filtering.

Two dimensional ordered filtering.

N dimensional ordered filtering.

Finds limits to contrast stretch an image

Estimate bounds for spatial transformation.

Create spatial filters for image processing.

Computes the linear filtering of the image I and the filter F.

Transform image.

Convert matrix from look up table (LUT).

Performs filtered back-projection on the projections in PROJ to reconstruct an approximation of the original image.

Performs non-maximum supression on the given edge data.

Calculates the 2D-Radon transform of the matrix I at angles given in THETA.

Filters the parallel ray projections in the columns of PROJ, according to the filter type chosen by TYPE.

Computes matrix B by using A as an index to lookup table LUT.

Perform area opening.

Create connectivity array.

Perform morphological bottom hat filtering.

Perform morphological closing.

Perform morphological dilation.

Perform morphological erosion.

Perform morphological opening.

Perform morphological top hat filtering.

Perform morphological gradient.

Return the heights of a non-flat structuring element.

Get neighbors relative position and height.

Return the neighborhood of structuring element SE.

Decompose structuring element.

Say if a structuring element object is flat or not.

Reflect structuring element of strel object.

Create a strel (structuring element) object for morphology operations.

Generate a new structuring element, which is SE translated in rows and columns as expressed in the offset 2-dimensional array V.

Read header of an Analyze 7.5 file.

Read image data of an Analyze 7.5 file.

Write image data to an Analyze 7.5 file.

Read EXIF information from JPEG image data.

Read value of TAGs from TIFF files.

Calculate block best size for block processing.

Processes image in blocks using user-supplied function.

Rearrange block columns back into matrix.

Apply function to matrix blocks

Rearrange blocks from matrix into columns.

Get pixel values.

Process matrix in sliding blocks with user-supplied function.

Convert a polygon to a region mask.

Select a Region Of Interest of an image based on color.

Returns a transformation structure T (see "help maketform" for the form of the structure) that can be further used to transform coordinates from one space (here denoted "RW" for "real world") to anoth

Crop image.

Pad (augment) a matrix for application of image processing algorithms.

Applies the spatial perspective homogeneous transformation P to the image IM.

Applies any geometric transformation to the image IM.

Resize image with interpolation

Rotate image about its center.

Rotation of a 2D matrix.

Applies a shear to the image M.

Translate a 2D image by (x,y) using Fourier interpolation.

Create structure for spatial transformations.

Arbitrary rotation and scaling of a gray-scale image using fast bilinear interpolation.

Given to dimensionnal coordinates from one space, returns two dimensionnal coordinates in the other space, as defined in the transform structure T.

Given to dimensionnal coordinates from one space, returns two dimensionnal coordinates in the other space, as defined in the transform structure T.

Creates an indexed image X from an intensitiy image I using multiple threshold levels.

Compute global image threshold.

Convert image to binary, black and white, by threshold.

Convert input image IM1 to double precision.

Convert input image IM1 to int16 precision.

Convert input image IM1 to single precision.

Convert input image IM1 to uint16 precision.

Convert input image IM1 to uint16 precision.

Reduce the number a colors of rgb or indexed image.

Return true if IMG is a black and white image.

Return true if IMG is an indexed image.

Return true if IMG is an indexed image.

Return true if IMG is a RGB image.

Convert labeled image into RGB.

Convert a matrix to an intensity image.

Convert RGB image or colormap to grayscale.

Create checkerboard.

Return display range of image.

Check if argument is valid connectivity.

Check if argument is valid colormap.

Checks for correct number of arguments.

Check if argument is a valid string.

Convert number to ordinal string.

Pad array or matrix.

Create computational phantom head.

Package: image