Purpose

The module Checksum calculates a checksum of all voxels of an image.

It also computes the Number of Voxels, Sum of Voxels, Minimum, and Maximum values.

It is useful to check with a certain probability whether images are identical without comparing the images directly or without the need to store test results. It also allows for composing a final report from results from other Checksum modules by special support for cascading many Checksum modules.

Usage

Press Calculate or select Auto Compute once the module is connected to an image input.

If you also want to include results from other Checksum modules, connect their report string to the Cascade Input field of your module.

Details

The checksum is calculated as

Checksum = Sum(Voxel Value * Voxel index)

Windows

Default Panel

../../../Modules/ML/MLDiagnosis/mhelp/Images/Screenshots/Checksum._default.png

Input Fields

input0

name: input0, type: Image

Parameter Fields

Field Index

Auto Compute: Bool Maximum: Double
Calculate: Trigger Minimum: Double
Cascade Input: String Number of Voxels: Integer
Checksum: Double Post ML Error: Bool
Comparison Okay: Bool Report: String
Control Checksum: Double Status: String
Epsilon Tolerance: Double Sum of Voxels: Double
IntChecksum: Integer Test Description: String

Visible Fields

Control Checksum

name: controlCheckSum, type: Double, default: 0

Sets the expected checksum.

Epsilon Tolerance

name: epsilon, type: Double, default: 0

Sets the maximal allowed difference between the checksum and control checksum.

Auto Compute

name: autoCompute, type: Bool, default: FALSE

If checked, the checksum is always updated on all input or field changes.

Post ML Error

name: postMLError, type: Bool, default: FALSE

Sets whether an ML error is posted if a checksum error occurs.

Cascade Input

name: cascadeInput, type: String

Connect a report from a previous Checksum module.

Test Description

name: description, type: String, default: Checksum Test

Shows what this module checks.

Number of Voxels

name: numVoxel, type: Integer, persistent: no

Shows the number of voxels for which a checksum was computed.

Sum of Voxels

name: voxelSum, type: Double, persistent: no

Shows the sum of the voxel values for which a checksum was computed.

Minimum

name: minimum, type: Double, persistent: no

Shows the minimum value of voxels for which the checksum was computed.

Maximum

name: maximum, type: Double, persistent: no

Shows the maximum value of voxels for which the checksum was computed.

Checksum

name: checkSum, type: Double, persistent: no

Shows the calculated checksum.

IntChecksum

name: intChecksum, type: Integer, persistent: no, deprecated name: checkSumInt

Displays the checksum as an integer, even in cases of precision loss.

Comparison Okay

name: comparisonOkay, type: Bool, persistent: no

Shows whether the difference between checksum and control checksum is smaller than epsilon.

Status

name: status, type: String, persistent: no

Shows the module’s status.

Report

name: report, type: String, persistent: no

Shows a composed report from this and previous Checksum modules.

Calculate

name: calculateChecksum, type: Trigger, deprecated name: processIn0Pages

When pressed, a new checksum is calculated.