Independent PHP image codecs

AlphaType

ContextBuffer

Mutable request-scoped MQ states: seven state bits and one MPS bit per context.

MqDecoder

MQ decoding, ISO/IEC 15444-1 Annex C; also used by JBIG2.

ChannelDefinition

Original cdef channel and association; outputChannel identifies its returned plane.

Codec

ColorInformation

Encoded colour interpretation retained separately from exact component values.

ColorSpecification

One original JPEG 2000 colr alternative, including its exact method payload.

ComponentPlane

Row-padded, MSB-first samples; signed samples use precision-bit two's complement.

DecodeBudget

One decoding operation owns all accounting, including global segments and intermediate buffers.

DecodeLimits

Explicit per-request ceilings, checked before allocation or iteration.

DecodeRequest

Original encoded bytes and explicit codec parameters; no file or network access.

DecodedImage

Component planes preserve precision, sampling geometry, colour metadata and alpha association.

Decoder

ArithmeticContext

Annex A integer/IAID procedures; adapted from PDF.js ce871674, Apache-2.0.

ArithmeticStates

One segment's statistics survive separately byte-framed refinement MQ substreams.

BitInput

Bounded byte/bit view over an immutable segment; no implicit zero padding.

Bitmap

Packed JBIG2 pixels, zero white/one black; page export explicitly reverses PDF polarity.

GenericBitmapDecoder

T.88 6.2/6.3, context layouts adapted from PDF.js ce871674, Apache-2.0.

HalftoneDecoder

T.88 6.6/6.7 and Annex C, including skipped grid cells and all composition operators.

HuffmanSelection

Standard/custom selection order, including Huffman-coded refinement substreams.

HuffmanTable

Annex B canonical codes, bounded without a recursive tree; PDF.js Apache-2.0 adaptation.

Jbig2Decoder

Pure PHP JBIG2; one request owns global segments, page state, contexts and resource accounting.

Jbig2Session

Segment DAG, page composition and resource lifetimes; no cross-document mutable state.

MmrBitmapDecoder

T.88 6.2.6: bounded T.6 rows, prohibited extensions, optional/required EOFB.

MmrBits

A shared bounded bit cursor; peeking preserves work accounting.

MmrCodes

Adapted from PDFToolkit Reader CCITT, Copyright PDFToolkit contributors, MIT.

MmrRow

Adapted from PDFToolkit Reader CCITT, Copyright PDFToolkit contributors, MIT.

MmrRowReader

Adapted from PDFToolkit Reader CCITT, Copyright PDFToolkit contributors, MIT.

PatternDictionary

RegionBitmap

RegionInfo

Segment

Immutable segment transport and explicit reference/retention metadata.

SegmentReader

T.88 7.2 and Annex D: sequential, random access and PDF embedded organizations.

StandardTables

T.88 Annex B.5; transcribed via PDF.js ce871674, Copyright Mozilla Foundation, Apache-2.0.

SymbolDictionary

Exported symbols and optional retained bitmap arithmetic contexts, owned by one request.

SymbolDictionaryDecoder

T.88 6.5 and 7.4.2; direct, collective and refinement/aggregate symbols.

TextParameters

T.88 text/aggregate region parameters, independent of the segment transport.

TextRegionDecoder

T.88 6.4; arithmetic/Huffman text and refinement, all corners/transposition/operators.

BitModel

T.800 Annex D. Scan organization adapted from Mozilla PDF.js (Apache-2.0),

Box

Boxes

Codeblock

Codestream

One codestream owns its headers, tile parts, packet state and output buffers.

Codeword

CodingStyle

Component

ComponentTransform

T.801 J.3.1.1.1 and Annex K; returns native sample values, before final clipping.

ContainerMetadata

ExtensionHeader

Header

Input

A bounded view; all lengths are checked before slicing or advancing.

Jp2Container

JP2 and the first JPX compositing layer, with in-memory fragment resolution only.

Jpeg2000Decoder

MarkerSeries

Nonlinearity

T.801 Annex K: point transforms operate on native, unshifted samples.

Packet

PacketBits

PacketReader

PlaneWriter

PrecinctBand

Quantization

RawBits

Rect

Resolution

Subband

TagTree

Tile

TileComponent

TileGeometry

T.800 B.3–B.7: geometry is retained in the reference grid, including odd origins.

TileOutput

Wavelet

T.800 F.3: lifting on the absolute grid; integer 5/3 and double 9/7.

CoefficientBuffer

Packed signed coefficients avoid one PHP array/hash entry per coefficient. @internal

EntropyBits

Entropy bytes stop strictly at markers; restart ordering belongs to the scan. @internal

HuffmanTable

Canonical codes from ITU T.81 Annex C; no recursively allocated tree. @internal

InverseTransform

Separable inverse DCT from the mathematical definition in ITU T.81 A.3.3. @internal

JpegComponent

Frame component and its request-local progressive state. @internal

JpegDecoder

PDF DCTDecode: eight-bit Huffman sequential and progressive JPEG.

JpegInput

Bounded cursor shared by marker and entropy readers; never scans for recovery. @internal

JpegScan

Request-local sequential/progressive entropy decoding (ITU T.81 Annexes F/G).

JpegSession

Marker parsing and one bounded image's state. @internal

MarkerBudget

Includes restart markers as well as outer segments. @internal

MalformedImage

PhpDecoder

Pure PHP dispatch; every call receives its own decoding state and resource budget.

ResourceLimit

UnsupportedFeature