The Rgb2gray () function cannot be used in octave

When the image is loaded in octave and turned into grayscale, it is found that the Rgb2gray () function does not exist, the Internet searches for a bit, the StackOverflow on the relevant explanation, as follows:

The problem is so you didn ' t load your packages. When you type pkg list can find which ones is loaded by a asterisk in front of their names. Load a package with pkg load image .

Have to load a packages are that thing the most users find strange if you compare with other languages, such as Pyth On, Perl, or C + +, would you expect them to import , use , or #include every libraries available in the system by default? Seeoctave ' s FAQ for more details.

Originally octave the default state of the missing related packages, processing, signal processing aspects of the package, we need to manually install.

Go to SourceForge to download the relevant package, put it on the octave search path, and execute the installation command on the octave command line:

The Rgb2gray () function requires an image package to be installed.

Attach the relevant package on the SourceForge octave:

Packages

These packages is meant for the current versions of Octave. See the unmaintainedsection for information on older versions.

Bim

Package for solving diffusion advection Reaction (DAR) Partial differential equations

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Bsltl

The BSLTL package was a free collection of octave/matlab routines for working with the Biospeckle laser technique

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Cgi

Common Gatway Interface for Octave

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Communications

Digital Communications, Error correcting Codes (Channel code), Source code functions, modulation and Galois fields

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Control

computer-aided Control System Design (CACSD) Tools for GNU Octave, based on the proven Slicot Library

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Data-smoothing

Algorithms for smoothing Noisy data

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Database

Interface to SQL databases, currently only PostgreSQL using LIBPQ

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Dataframe

Data manipulation Toolbox similar to R data

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Dicom

Digital Communications in Medicine (DICOM) file IO

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Divand

Divand performs an n-dimensional variational analysis (interpolation) of arbitrarily located observations

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Doctest

The Octave-forge doctest package finds specially-formatted blocks of example code within documentation files

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Econometrics

Econometrics functions including MLE and GMM based techniques

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Fem-fenics

Pkg for the resolution of partial differential equations based on fenics

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Financial

Monte Carlo Simulation, options pricing routines, financial manipulation, plotting functions and additional date Manipulat Ion Tools

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Fits

The Octave-fits package provides functions for reading, and writing FITS (flexible Image Transport System) files

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Fl-core

The package contains code for basic functions in Fuzzy Logic for Octave

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Fpl

Collection of routines to export data produced by finite Elements or finite Volume simulations in formats used by some Vis Ualization Programs

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Fuzzy-logic-toolkit

A mostly matlab-compatible Fuzzy Logic toolkit for Octave

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Ga

Genetic optimization Code

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General

General Tools for Octave

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Generate_html

This is provides functions for generating HTML pages, contain the help texts for a set of functions

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Geometry

Library for geometric computing extending MATGEOM functions

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Image

The Octave-forge Image package provides functions for processing images

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Image-acquisition

The Octave-forge Image aquisition package provides functions to capture images from connected devices

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Instrument-control

Low Level I/O functions for serial, I²C, parallel, TCP, GPIB, vxi11 and USBTMC interfaces

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Interval

The interval package for real-valued interval arithmetic allows one to evaluate functions over subsets of their domain

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Io

Input/output in external formats.

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Java

Provides Java interface with Oo-like Java objects manipulation

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Level-set

Routines for calculating the time-evolution of the Level-set equation and extracting geometric information from the level- Set function

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Linear-algebra

Additional linear algebra code, including general SVD and matrix functions

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Lssa

A package implementing tools to compute spectral decompositions of irregularly-spaced time series

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Ltfat

The Large time/frequency Analysis Toolbox (LTFAT) are a matlab/octave toolbox for working with time-frequency analysis, WAV Elets and Signal processing

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Mapping

Simple mapping and GIS. SHP and Raster file functions

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Mechanics

Library with functions useful for numerical computation on classical mechanics and structural analysis

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Miscellaneous

Miscellaneous tools that don ' t fit somewhere else

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Mpi

Octave bindings for basic Message passing Interface (MPI) functions for parallel computing

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Msh

Create and manage triangular and tetrahedral meshes for finite Element or finite Volume PDE solvers

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Mvn

Multivariate normal distribution clustering and utility functions

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Nan

A Statistics and machine learning Toolbox for data with and w/o missing values

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Ncarray

Access a single or a collection of NetCDF files as a multi-dimensional array

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netCDF

A MATLAB compatible NetCDF interface for Octave

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Nurbs

Collection of routines for the creation, and manipulation of Non-uniform Rational B-splines (NURBS), based on the NURBS to Olbox by Mark Spink

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OCs

Package for solving DC and transient electrical circuit equations

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Octcdf

A NetCDF Interface for Octave

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Octclip

This is the allows to does Boolean operations with polygons using the Greiner-hormann algorithm

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Octproj

This package allows to call functions of PROJ

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Odepkg

A solving ordinary differential equations and more

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Optics

Functions covering various aspects of optics

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Optim

Non-linear Optimization Toolkit

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Optiminterp

An optimal interpolation toolbox for octave

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Parallel

Parallel Execution Package

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Quaternion

quaternion package for GNU Octave, includes a quaternion class with overloaded operators

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Queueing

The queueing package provides functions for queueing networks and Markov chains analysis

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secs1d

A drift-diffusion Simulator for 1d semiconductor devices

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Secs2d

A drift-diffusion Simulator for 2d Semiconductor devices

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Secs3d

A drift-diffusion Simulator for 3d semiconductor devices

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Signal

Signal processing tools, including filtering, windowing and display functions

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Sockets

Socket functions for networking from within octave

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Sparsersb

Interface to the LIBRSB package implementing the RSB sparse matrix format

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Specfun

Special functions including ellipitic functions, etc

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Splines

Additional spline functions

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Statistics

Additional statistics functions for Octave

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Stk

The STK is a (not so) Small Toolbox for Kriging

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Strings

Additional functions for manipulation and analysis of strings

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struct

Additional Structure manipulations functions

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Symbolic

The Octave-forge symbolic package adds symbolic calculation features to GNU Octave

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Tisean

Port of Tisean 3

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Tsa

Stochastic concepts and maximum entropy methods for time series analysis

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Video

A wrapper for FFmpeg ' s Libavformat and Libavcodec, implementing Addframe, Avifile, Aviinfo and Aviread

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Vrml

3D Graphics using VRML

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Windows

Provides COM interface and additional functionality on Windows

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Zeromq

ZeroMQ Bindings for GNU Octave

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Renamed or moved Packages

Some packages has been renamed or merged over time. When Thishappens, the a dummy transitional package is created--the empty anddependent on the IT new package. After some time, those is removedas well. The following is a list of such packages:

• Combinatorics-merged into miscellaneous and Specfun
• Openmpi_ext-renamed MPI.
• Physicalconstants-merged into miscellaneous.
• Time-merged into Financial.

unmaintained Packages

The Octave Forge project is a location to develop multiple packages for gnuoctave. With time, some packages become unmaintained, usually because the Originalauthor no longer requires it and no one steps up To take the its position. Without amaintainer or active user base, and as Octave evolves, we don't know how usablethey is, so we can no longer hon Estly recommend their use.

They is still stored and release tarballs can be downloaded from Ourfile release System (same for the very oldmonolithic R eleases). However, many of them has accumulated bug fixes and new features in Themercurial orsvnrepositories, it simply happens tha T maintainer has prepared a release. Because of this, we encourage users to check the development sources, not the releasedtarballs. Furthermore,bug reports for those packagescontinue to being welcome, and anyone wishing to take up the position of maintainer , please contactus through themaintainers mailing list.

The complete list of unmaintained packages is:

• Actuarial
• Ad
• Ann
• Audio
• Benchmark
• Bioinfo
• Civil-engineering
• Engine
• Fenv
• Gnuplot
• Es.
• Informationtheory
• Integration
• Irsa
• Missing-functions
• Multicore
• Nlwing2
• Nnet
• Oct2mat
• Octgpr
• Odebvp
• Outliers
• Pdb
• Plot
• Simp
• Special-matrix
• Symband
• Tcl-octave
• Xraylib
• Zenity

Reference:

[1]:http://octave.sourceforge.net/

[2]:http://octave.sourceforge.net/packages.php

The Rgb2gray () function cannot be used in octave