# Overview

## Purpose

This manual describes program operation and command-line usage for ALE version .

## Parameter Meta-syntax

When describing parameter syntax, the following conventions are used in this manual:

Parameter Meta-syntax
<foo> | A required parameter called foo. |
[<foo>] | An optional parameter called foo.
[<foo>]* | Zero or more parameters foo.

## Command-line syntax for Image Processing

The following command-line invocation can be used to process a series of frames into an output file:

ale [<option>]* <original-frame> [<supplemental-frame>]* <output-file>

For experimental argument scope syntax, see .

Option Arguments
Default Settings

Certain basic modes of operation, emphasizing image quality, speed, or other rendering characteristics, are established in the form of default settings. For more information, see:

Other options

For information about other options, see:

Image Files

ALE can be configured at compile time to use one of two different file handlers. Execute 'ale --version' to determine which file handler is being used. The table below outlines the supported formats for each file handler.

Supported image file formats
Version Message | File Types Supported
--- | ---
File handler: ImageMagick | Input and output files can be any of the formats supported by ImageMagick. |
File handler: PPM | Input files must be PPM, and output files are written as PPM.

Note that many external programs, including ImageMagick's command line utilities, can be used to convert between PPM and other formats.

See the README included in the source distribution for more information about compile-time configuration of file handlers.

Usage of extended PPM syntax for specifying image metadata is outlined in .

## Command-line syntax for Version Information

The following command-line invocation can be used to print version information and build options:

ale --version

The following is sample output from this invocation:

ALE Version: File handler: ImageMagick Color data: SINGLE Coordinate data: SINGLE DFT: FFTW3 Threads: POSIX Assertions: Enabled Optimizations: Enabled

The first line of output indicates the program version; the remaining lines reflect the build options selected at compile time.

For more information about build options, see the README file included in the source distribution.

## Command-line syntax for Help Output

When invoked with no arguments, or an insufficient number of file arguments, ALE outputs a help message specifying command-line usage and available help topics. The following is a sample invocation:

ale
Help Topics

More information about specific help topics can be obtained with an invocation of the following form:

ale <help option>

Available help options, and their corresponding help topics, are outlined below:

--hu Usage (this message). --hq Default settings. --hf Image files. --he Exclusion regions. --ha Alignment (not exposure-related). --hr Rendering (not exposure-related). --hx Exposure. --ht Transformation data files. --hc Control points. --hl Filtering (PSFs, rendering chains). --hd Devices. --hi User Interfaces. --hp Process details. --hs Argument scope (Experimental). --hv Video stream processing (Experimental). --h3 3D Modeling (Experimental). --hz Undocumented options. --hA Concatenate all help pages.