PredictorFilter
in package
FinalYes
PDF predictor filter — applies/removes PNG and TIFF prediction as specified in ISO 32000-2 §7.4.4.4.
Predictors reduce redundancy in row-based data (e.g., image scanlines) before compression. They are used as a pre-processing step with FlateDecode and LZWDecode.
Predictor values: 1 = No prediction (default) 2 = TIFF Predictor 2 (horizontal differencing) 10 = PNG None 11 = PNG Sub 12 = PNG Up 13 = PNG Average 14 = PNG Paeth 15 = PNG Optimum (per-row selector via tag byte)
Table of Contents
Methods
- __construct() : mixed
- decode() : string
- encode() : string
Methods
__construct()
public
__construct([int $predictor = 1 ][, int $columns = 1 ][, int $colors = 1 ][, int $bitsPerComponent = 8 ]) : mixed
Parameters
- $predictor : int = 1
- $columns : int = 1
- $colors : int = 1
- $bitsPerComponent : int = 8
decode()
public
decode(string $data) : string
Parameters
- $data : string
Return values
stringencode()
public
encode(string $data) : string
Parameters
- $data : string