Selection Elements
Amazon Textract can detect selection elements such as option buttons (radio buttons), check boxes, underlined, and circled text on a document page. Selection elements can be detected in form data and in tables. For example, when the following table is detected on a form, Amazon Textract detects the check boxes in the table cells.
|
|
Agree |
Neutral |
Disagree |
|
Good Service |
☑ |
☐ |
☐ |
|
Easy to Use |
☐ |
☑ |
☐ |
|
Fair Price |
☑ |
☐ |
☐ |
Detected selection elements are returned as Block objects in the responses from AnalyzeDocument and GetDocumentAnalysis.
Below is a table that provides examples of the different selectable types supported by Amazon Textract.
|
Selectable Type |
Example |
Radio Button |
Yes ○ No ● |
Checkbox |
Yes ☐ No ☑ |
Underlined Words |
Yes No |
Circled Words |
|
Crossed Out Words |
|
Additionally Amazon Textract can detect implicit clickables, or clickables that are structured as questions and answered by marking one of several answers. These are returned the same way clickables are.
Note
You can use the FeatureTypes input parameter to retrieve
information about key-value pairs, tables, or both. For example, if you
filter on tables, the response includes the selection elements that are
detected in tables. Selection elements that are detected in key-value pairs
aren't included in the response.
Information about a selection element is contained in a Block
object of type SELECTION_ELEMENT. To determine the status of a
selectable element, use the SelectionStatus field of the
SELECTION_ELEMENT block. The status can be either
SELECTED or NOT_SELECTED. For
example, the value of SelectionStatus for the previous image is
SELECTED.
A SELECTION_ELEMENT
Block object is associated with either a key-value pair or a table
cell. A SELECTION_ELEMENT
Block object contains bounding box information for a selection
element in the Geometry field. A SELECTION_ELEMENT
Block object isn't a child of a PAGE
Block object.
Form Data (Key-Value Pairs)
A key-value pair is used to represent a selection element that's detected
on a form. The KEY block contains the text for the selection
element. The VALUE block contains the SELECTION_ELEMENT block.
The following diagram shows how selection elements are represented by Block objects.
For more information about key-value pairs, see Form Data (Key-Value Pairs).
The following JSON snippet shows the key for a key-value pair that contains a
selection element (male ☑). The child ID
(Id bd14cfd5-9005-498b-a7f3-45ceb171f0ff) is the ID of the WORD block that
contains the text for the selection element (male). The
value ID (Id 24aaac7f-fcce-49c7-a4f0-3688b05586d4) is the ID of the
VALUE block that contains the SELECTION_ELEMENT
block object.
{ "Relationships": [ { "Type": "VALUE", "Ids": [ "24aaac7f-fcce-49c7-a4f0-3688b05586d4" // Value containing Selection Element ] }, { "Type": "CHILD", "Ids": [ "bd14cfd5-9005-498b-a7f3-45ceb171f0ff" // WORD - male ] } ], "Confidence": 94.15619659423828, "Geometry": { "BoundingBox": { "Width": 0.022914813831448555, "Top": 0.08072036504745483, "Left": 0.18966935575008392, "Height": 0.014860388822853565 }, "Polygon": [ { "Y": 0.08072036504745483, "X": 0.18966935575008392 }, { "Y": 0.08072036504745483, "X": 0.21258416771888733 }, { "Y": 0.09558075666427612, "X": 0.21258416771888733 }, { "Y": 0.09558075666427612, "X": 0.18966935575008392 } ] }, "BlockType": "KEY_VALUE_SET", "EntityTypes": [ "KEY" ], "Id": "a118dc43-d5f7-49a2-a20a-5f876d9ffd79" }
The following JSON snippet is the WORD block for the word Male. The WORD block also has a parent LINE block.
{ "Geometry": { "BoundingBox": { "Width": 0.022464623674750328, "Top": 0.07842985540628433, "Left": 0.18863198161125183, "Height": 0.01617223583161831 }, "Polygon": [ { "Y": 0.07842985540628433, "X": 0.18863198161125183 }, { "Y": 0.07842985540628433, "X": 0.2110965996980667 }, { "Y": 0.09460209310054779, "X": 0.2110965996980667 }, { "Y": 0.09460209310054779, "X": 0.18863198161125183 } ] }, "Text": "Male", "BlockType": "WORD", "Confidence": 54.06439208984375, "Id": "bd14cfd5-9005-498b-a7f3-45ceb171f0ff" },
The VALUE block has a child (Id f2f5e8cd-e73a-4e99-a095-053acd3b6bfb) that is the SELECTION_ELEMENT block.
{ "Relationships": [ { "Type": "CHILD", "Ids": [ "f2f5e8cd-e73a-4e99-a095-053acd3b6bfb" // Selection element ] } ], "Confidence": 94.15619659423828, "Geometry": { "BoundingBox": { "Width": 0.017281491309404373, "Top": 0.07643391191959381, "Left": 0.2271782010793686, "Height": 0.026274094358086586 }, "Polygon": [ { "Y": 0.07643391191959381, "X": 0.2271782010793686 }, { "Y": 0.07643391191959381, "X": 0.24445968866348267 }, { "Y": 0.10270800441503525, "X": 0.24445968866348267 }, { "Y": 0.10270800441503525, "X": 0.2271782010793686 } ] }, "BlockType": "KEY_VALUE_SET", "EntityTypes": [ "VALUE" ], "Id": "24aaac7f-fcce-49c7-a4f0-3688b05586d4" }, }
The following JSON is the SELECTION_ELEMENT block. The value of
SelectionStatus indicates that the check box is
selected.
{ "Geometry": { "BoundingBox": { "Width": 0.020316146314144135, "Top": 0.07575977593660355, "Left": 0.22590067982673645, "Height": 0.027631107717752457 }, "Polygon": [ { "Y": 0.07575977593660355, "X": 0.22590067982673645 }, { "Y": 0.07575977593660355, "X": 0.2462168186903 }, { "Y": 0.1033908873796463, "X": 0.2462168186903 }, { "Y": 0.1033908873796463, "X": 0.22590067982673645 } ] }, "BlockType": "SELECTION_ELEMENT", "SelectionStatus": "SELECTED", "Confidence": 74.14942932128906, "Id": "f2f5e8cd-e73a-4e99-a095-053acd3b6bfb" }
Table Cells
Amazon Textract can detect selection elements inside a table cell. For example, the cells in the following table have check boxes.
|
|
Agree |
Neutral |
Disagree |
|
Good Service |
☑ |
☐ |
☐ |
|
Easy to Use |
☐ |
☑ |
☐ |
|
Fair Price |
☑ |
☐ |
☐ |
A CELL block can contain child SELECTION_ELEMENT
objects for selection elements and child WORD blocks for
detected text.
For more information about tables, see Tables.
The TABLE Block object for the previous table looks similar
to this.
{ "Geometry": {.....}, "Relationships": [ { "Type": "CHILD", "Ids": [ "652c09eb-8945-473d-b1be-fa03ac055928", "37efc5cc-946d-42cd-aa04-e68e5ed4741d", "4a44940a-435a-4c5c-8a6a-7fea341fa295", "2de20014-9a3b-4e26-b453-0de755144b1a", "8ed78aeb-5c9a-4980-b669-9e08b28671d2", "1f8e1c68-2c97-47b2-847c-a19619c02ca9", "9927e1d1-6018-4960-ac17-aadb0a94f4d9", "68f0ed8b-a887-42a5-b618-f68b494a6034", "fcba16e0-6bd7-4ea5-b86e-36e8330b68ea", "2250357c-ae34-4ed9-86da-45dac5a5e903", "c63ad40d-5a14-4646-a8df-2d4304213dbc", // Cell "2b8417dc-e65f-4fcd-aa0f-61a23f1e8cb0", "26c62932-72f0-4dc2-9893-1ae27829c060", "27f291cc-abf4-4c23-aa24-676abe99cb1e", "7e5ce028-1bcd-4d9f-ad42-15ac181c5b47", "bf32e3d2-efa2-4fc1-b09b-ab9cc52ff734" ] } ], "BlockType": "TABLE", "Confidence": 99.99993896484375, "Id": "f66eac36-2e74-406e-8032-14d1c14e0b86" }
The CELL BLOCK object (Id
c63ad40d-5a14-4646-a8df-2d4304213dbc) for the cell that contains the check
box Good Service looks like the following. It includes
a child Block (Id = 26d122fd-c5f4-4b53-92c4-0ae92730ee1e) that
is the SELECTION_ELEMENT
Block object for the check box.
{ "Geometry": {.....}, "Relationships": [ { "Type": "CHILD", "Ids": [ "26d122fd-c5f4-4b53-92c4-0ae92730ee1e" // Selection Element ] } ], "Confidence": 79.741689682006836, "RowSpan": 1, "RowIndex": 3, "ColumnIndex": 3, "ColumnSpan": 1, "BlockType": "CELL", "Id": "c63ad40d-5a14-4646-a8df-2d4304213dbc" }
The SELECTION_ELEMENT Block object for the check box is as
follows. The value of SelectionStatus indicates that the check
box is selected.
{ "Geometry": {.......}, "BlockType": "SELECTION_ELEMENT", "SelectionStatus": "SELECTED", "Confidence": 88.79517364501953, "Id": "26d122fd-c5f4-4b53-92c4-0ae92730ee1e" }
