2D Barcode Quick Recognition

## 2D Barcode Quick Recognition

Identifies 2D barcode (QR code, Data Matrix, etc.) information within a specified region of an image.

## Module Principle
This module performs the localization and decoding process for 2D barcodes.

### Algorithm Workflow
1. Locate the precise region of the 2D barcode in the image based on the generation rules of the selected barcode type.
2. Decode and perform error correction based on the characteristics of the code.
3. Output the decoded string.

## Usage Scenarios
The 2D barcode recognition module is used to locate and identify 2D barcodes within specified regions. It tolerates target 2D barcodes rotated at arbitrary angles and those with a certain degree of tilt.

### Preceding Modules
The preceding modules for this module are typically camera image acquisition or image preprocessing modules.

## Parameter Configuration Description

### 2D Barcode Type:
*   **QR:** A Quick Response matrix code characterized by square finder patterns (return-shaped blocks) at three corners.
*   **Aztec:** A matrix 2D barcode characterized by a bullseye-style locator in the center.
*   **ECC200:** A 2D matrix code (Data Matrix) characterized by an "L" shaped boundary formed by solid lines on two adjacent sides.
*   **PDF417:** A stacked linear 2D barcode, mainly used in identity documents and logistics.
*   **GS1 QR:** A QR code supporting GS1 application identifiers syntax, mainly used in retail product packaging.
*   **GS1 Aztec:** An Aztec code supporting GS1 application identifiers syntax, mainly used in medical labeling, logistics, and computing fields.
*   **GS1 DataMatrix:** A Data Matrix code supporting GS1 application identifiers syntax, mainly used in industrial traceability.

### Max Barcodes per ROI:
The maximum number of 2D barcodes to identify within a single detection region.

### Prefix Character Filter:
Filters 2D barcode recognition results to include only those starting with specified characters.

### Character Count Judgment:
Criteria for judging the number of characters in the 2D barcode recognition result.

### 2D Barcode Position Filter:
*   **Ignore:** No position filtering is applied to the recognition results.
*   **Topmost Barcode:** Retains only the 2D barcode located at the topmost position in the results.
*   **Bottommost Barcode:** Retains only the 2D barcode located at the bottommost position in the results.
*   **Leftmost Barcode:** Retains only the 2D barcode located at the leftmost position in the results.
*   **Rightmost Barcode:** Retains only the 2D barcode located at the rightmost position in the results.

### 2D Barcode Color:
*   **Any:** Recognizes 2D barcodes that are either black or white.
*   **Black:** Recognizes only black 2D barcodes.
*   **White:** Recognizes only white 2D barcodes.

![](/media/202602/二维码高级参数_1770278777.png)

### Max Read Attempts:
The maximum number of times to preprocess the image and re-attempt recognition if no 2D barcode result is found.

### Learn & Train:
Click this button to learn recognition parameters if the 2D barcode cannot be identified.

### Timeout:
The maximum detection time allowed for recognizing a 2D barcode.

### Read Grade:
*   **Standard:** Uses parameters for standard mode recognition.
*   **Enhanced:** Uses parameters for enhanced mode recognition.
*   **Maximum:** Uses parameters for maximum mode recognition.
*   **Extreme:** Uses image enhancement techniques along with maximum mode parameters.

### 2D Barcode Center Filter:
*   **Center X:** Filters recognition results where the horizontal coordinate of the 2D barcode center falls within this range.
*   **Center Y:** Filters recognition results where the vertical coordinate of the 2D barcode center falls within this range.

### Output String on Failure:
The character string to output when no 2D barcode is recognized.

### Display Center Info:
Displays the center coordinates of all recognized 2D barcodes to facilitate viewing for center filtering.

![](/media/202602/二维码显示设置_1770280361.png)

### Display Settings:
Configures parameters related to ROI, 2D barcode regions, and 2D barcode information display.

![](/media/202602/位置调整_1770106939.png)

### Position Adjustment:
Manually adjusts ROI-related parameters.

### ROI Type:
*   **Rotated Rectangle:** A rectangle that can be moved, resized, and rotated. Its angle can be any value from 0 to 360 degrees.

### ROI Mode:
*   **Single ROI:** Only one 2D barcode recognition detection region.
*   **Array ROI:** Supports multiple 2D barcode recognition regions.

### ROI Source:
*   **Manual ROI:** In this mode, ROI-related parameters can be directly set within this module.
*   **Referenced ROI:** In this mode, ROI-related parameters cannot be modified in this module; they must be imported from an upstream module.

### Position Correction:
*   **Disabled:** No position adjustment is made to the set ROI.
*   **Pose Correction:** Adjusts the position of the set ROI based on the input value.

## Output Description

### Run Result:
Indicates whether the 2D barcode recognition was successful.

### 2D Barcode Count:
The number of 2D barcodes recognized.

### Character Count:
The number of characters in the recognized 2D barcode result.

### Character Output:
The recognized 2D barcode result string.

### 2D Barcode Region Array:
The image regions where the recognized 2D barcodes are located.

### ROI Count:
The number of ROIs.

### ROI Status Array:
Indicates whether a 2D barcode was recognized in each ROI.

## Precautions
1. When using this module, please place the licensed `halcon.dll` and `halconc.dll` files obtained from MVTec into the software release package, then restart the software to enable functionality.
2. This module is only supported on Windows 10 or later operating systems.

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Click here to jump to the corresponding Chinese manual page: [2D Barcode Quick Recognition](/doc/153)