3.2. ZBarImageScanner Class Reference

class ZBarImageScanner

Inherits from:NSObject

This is a low-level interface for programmatically scanning images without a user interface. If you want to scan images manually selected by the user (from the photo library or using the camera), you may prefer to use a ZBarReaderController instead.

This class is a wrapper around a zbar_image_scanner_t C object (q.v.)

3.2.1. Properties

BOOL enableCache

Enable the inter-frame consistency cache. Set to YES for scanning video or NO for scanning images.

ZBarSymbolSet results

Decoded symbols resulting from the last scan.

3.2.2. Instance Methods

- (void) parseConfig:(NSString*)config

Apply scanner/decoder configuration parsed from a string.

Config :A configuration setting of the form: symbology.config[=value].

- (void) setSymbology:(zbar_symbol_type_t)symbology config:(zbar_config_t)config to:(int)value

Apply generic scanner/decoder configuration.

Symbology :The symbology to effect, or 0 for all. Config :The configuration setting to adjust. Value :The value to set for the specific configuration/symbology.

- (NSInteger) scanImage:(ZBarImage*)image

Scan an image for barcodes using the current configuration. The image must be in Y800 format (8-bpp graysale).

Image :The ZBarImage to scan. Returns :The number of barcode symbols decoded in the image.

3.2.3. Constants

type zbar_config_t

ZBAR_CFG_ENABLE

Control whether specific symbologies will be recognized. Disabling unused symbologies improves performance and prevents bad scans.

ZBAR_CFG_EMIT_CHECK

Whether to include the check digit in the result data string. This value may be set individually for symbologies where it makes sense.

ZBAR_CFG_MIN_LEN

The minimum data length for a symbol to be valid, set to 0 to disable. Use with eg, I2/5 to avoid short scans. This value may be set individually for variable-length symbologies.

ZBAR_CFG_MAX_LEN

The maximum data length for which a symbol is valid, set to 0 to disable. Use with eg, I2/5 to enforce a specific range of data lengths. This value may be set individually for variable-length symbologies.

ZBAR_CFG_UNCERTAINTY

Number of “nearby” frames that must contain a symbol before it will be considered valid. This value may be set for individual symbologies.

ZBAR_CFG_POSITION

Whether to track position information.

ZBAR_CFG_X_DENSITY

The stride to use for scanning vertical columns of the image. This many pixel columns will be skipped between vertical scan passes. Useful for trading off between resolution and performance. This is a scanner setting (use 0 for the symbology).

ZBAR_CFG_Y_DENSITY

The stride to use for scanning horizontal columns of the image. This many pixel rows will be skipped between horizontal scan passes. Useful for trading off between resolution and performance. This is a scanner setting (use 0 for the symbology).