Aspose.OMR for .NET 22.8 Release Notes

What was changed

Known issues and limitations

Public API changes and backwards compatibility

This section lists all public API changes introduced in Aspose.OMR for .NET 22.8 that may affect the code of existing applications.

Added public APIs:

No changes.

Updated public APIs:

The following public APIs have been updated in this release:

Multiple write-in fields in VerticalChoiceBox

The OMR API can now process more than one write-in field per VerticalChoiceBox (text markup / JSON markup) element. The corresponding WriteIn (text markup / JSON markup) elements must have unique names.

When the bubble corresponding to the write-in field is marked, the name of the Answer element is added to the recognition results and the contents of the write-in field are stored in Images collection.

// Initialize Aspose.OMR engine
Aspose.OMR.Api.OmrEngine omrEngine = new Aspose.OMR.Api.OmrEngine();
// Recognize completed form
Aspose.OMR.Api.TemplateProcessor recognitionEngine = omrEngine.GetTemplateProcessor("demo/form.omr");
Aspose.OMR.Model.RecognitionResult recognitionResult = recognitionEngine.RecognizeImage("demo/result.png");
// Save write-in fields
int i = 0;
foreach(System.Drawing.Bitmap bitmap in recognitionResult.Images)
{
	string writeInPath = Path.Combine("demo", $"image{i++}.png");
	bitmap.Save(writeInPath);
}
string result = recognitionResult.GetCsv();
Console.WriteLine(result);

Recognition results: CSV

Element Name,Value,
"What does OMR stand for?","Own answer 1"

Recognition results: field contents

Backwards compatibility considerations

Aspose.OMR for .NET 22.7 and below can render a VerticalChoiceBox element with multiple write-in fields. However, the Images collection will store only one such field per VerticalChoiceBox element. This field must have the following properties:

• The name of the parent Answer element must be write-in.
• The name of the corresponding WriteIn element must be equal to the name of the VerticalChoiceBox element.

Otherwise, the contents of the field will not be stored in the Images collection, even if the corresponding bubble is marked.

Removed public APIs:

No changes.

Changes in application logic

This section lists any changes to the program architecture and form processing algorithms introduced in Aspose.OMR for .NET 22.8 that may affect the behavior of existing applications.

Additional positioning marker

To improve and speed up the processing of rotated scans of photos, a new positioning marker has been added to the upper right corner of printable OMR forms.

All forms generated with previous versions of Aspose.OMR for .NET (that lack that extra marker) will not be recognized by Aspose.OMR for .NET 22.8. The following error will be returned: “Found 4 reference points. Since version 22.8 we support only 5 reference points. Please generate template using latest version.”.

Previous versions of Aspose.OMR for .NET may be able to process forms generated with Aspose.OMR for .NET 22.8, but recognition results are not guaranteed to be correct.

Improved positioning marker detection

The algorithm for detecting OMR form positioning markers has been significantly improved. Now it can filter out additional elements on the form that might otherwise be mistaken for a position marker.

Usage examples

See the examples below to learn more about the changes introduced in this release:

Multiple write-in fields

This source code is backward compatible with Aspose.OMR for .NET 22.7 and below.

?container=Example
?block=Border
	border=Square
	border_size=5
?content=What does OMR stand for?
	font_style=Bold
	font_size=12
?vertical_choicebox=Definition
	top_padding=100
?answer=1
?content=Optical mark recognition
	font_style=Bold
	font_size=10
&answer
?answer=2
?content=Optical character recognition
	font_style=Bold
	font_size=10
&answer
?answer=write-in
?content=Own answer 1
	font_style=Bold
	font_size=10
?write_in=Definition
&answer
?answer=Custom answer
?content=Own answer 2
	font_style=Bold
	font_size=10
?write_in=Custom definition
&answer
&vertical_choicebox
&block
&container