Where does BitmapHelper live in the IronOCR API?

BitmapHelper is a static class in the DynamicTesseract namespace, shipped in IronOcr.dll. It derives from Object and exposes only static pixel-format and buffer-access methods, so it is never instantiated.

What does BitmapHelper do in IronOCR?

It provides low-level image helpers for the interop layer: ConvertArgb1555ToRGBA, ConvertRgb555ToRGBA, and ConvertRgb565ToRGBA promote 16-bit samples to RGBA, EncodeAsRGBA packs four channels into a UInt32, GetBPP reports bits per pixel, and the GetData and SetData methods read and write buffer samples.

Do you need BitmapHelper for normal OCR reading in C#?

No. BitmapHelper is part of the DynamicTesseract interop layer beneath IronOCR's reading API. For typical OCR, use the high-level input and result classes; reach for BitmapHelper only when custom code manipulates raw pixel data before the native engine reads it.

Class BitmapHelper

Inheritance

System.Object

BitmapHelper

Namespace: DynamicTesseract

Assembly: IronOcr.dll

Syntax

public static class BitmapHelper : Object

Reach for BitmapHelper when low-level OCR code has to convert pixel formats or touch a bitmap's raw bytes before handing the image to Tesseract. It is a static utility in the DynamicTesseract interop layer that sits under IronOCR's higher-level reading API, so most projects never call it directly. Code that drives the native engine itself, or that pre-processes image data for a custom scan path, is where it earns its place.

The class works on an AnyBitmap and on raw byte and pixel pointers, so it belongs to the stage that prepares image data, before the engine reads it. A typical caller has already decoded an image and now needs it in the packed RGBA layout the native pipeline expects, or needs to read and write individual samples in a buffer. BitmapHelper supplies the format conversions and the indexed accessors for that work without forcing a full re-decode of the image.

The members fall into three functional groups. The pixel-format converters, ConvertArgb1555ToRGBA, ConvertRgb555ToRGBA, and ConvertRgb565ToRGBA, promote a single packed 16-bit sample to 32-bit RGBA, and EncodeAsRGBA packs four Byte channels back into one UInt32. The typed buffer readers, GetDataBit, GetDataByte, GetDataQBit, GetDataUInt16, and GetDataUInt32, read a sample at an index from a pointer, and the matching SetDataBit, SetDataByte, SetDataQBit, SetDataUInt16, and SetDataUInt32 write one back. GetBPP reports the bits per pixel of an AnyBitmap, which tells you which converter and accessor width to use. Because the accessors take raw pointers, call them from an unsafe context and respect the buffer bounds yourself.

int bpp = BitmapHelper.GetBPP(bitmap);
uint rgba = BitmapHelper.EncodeAsRGBA(r, g, b, a);

For everyday reading, prefer the high-level API: the color correction how-to and the image quality how-to tune the image, and the advanced reading configuration how-to covers deeper engine control.

Methods

ConvertArgb1555ToRGBA(UInt32)

Declaration

public static uint ConvertArgb1555ToRGBA(uint val)

Parameters

Type	Name	Description
System.UInt32	val

Returns

Type	Description
System.UInt32

ConvertRgb555ToRGBA(UInt32)

Declaration

public static uint ConvertRgb555ToRGBA(uint val)

Parameters

Type	Name	Description
System.UInt32	val

Returns

Type	Description
System.UInt32

ConvertRgb565ToRGBA(UInt32)

Declaration

public static uint ConvertRgb565ToRGBA(uint val)

Parameters

Type	Name	Description
System.UInt32	val

Returns

Type	Description
System.UInt32

EncodeAsRGBA(Byte, Byte, Byte, Byte)

Declaration

public static uint EncodeAsRGBA(byte red, byte green, byte blue, byte alpha)

Parameters

Type	Name	Description
System.Byte	red
System.Byte	green
System.Byte	blue
System.Byte	alpha

Returns

Type	Description
System.UInt32

GetBPP(AnyBitmap)

Declaration

public static int GetBPP(AnyBitmap bitmap)

Parameters

Type	Name	Description
IronSoftware.Drawing.AnyBitmap	bitmap

Returns

Type	Description
System.Int32

GetDataBit(Byte*, Int32)

Declaration

public static byte GetDataBit(byte *data, int index)

Parameters

Type	Name	Description
System.Byte*	data
System.Int32	index

Returns

Type	Description
System.Byte

GetDataByte(Byte*, Int32)

Declaration

public static byte GetDataByte(byte *data, int index)

Parameters

Type	Name	Description
System.Byte*	data
System.Int32	index

Returns

Type	Description
System.Byte

GetDataQBit(Byte*, Int32)

Declaration

public static byte GetDataQBit(byte *data, int index)

Parameters

Type	Name	Description
System.Byte*	data
System.Int32	index

Returns

Type	Description
System.Byte

GetDataUInt16(UInt16*, Int32)

Declaration

public static ushort GetDataUInt16(ushort *data, int index)

Parameters

Type	Name	Description
System.UInt16*	data
System.Int32	index

Returns

Type	Description
System.UInt16

GetDataUInt32(UInt32*, Int32)

Declaration

public static uint GetDataUInt32(uint *data, int index)

Parameters

Type	Name	Description
System.UInt32*	data
System.Int32	index

Returns

Type	Description
System.UInt32

SetDataBit(Byte*, Int32, Byte)

Declaration

public static void SetDataBit(byte *data, int index, byte value)

Parameters

Type	Name	Description
System.Byte*	data
System.Int32	index
System.Byte	value

SetDataByte(Byte*, Int32, Byte)

Declaration

public static void SetDataByte(byte *data, int index, byte value)

Parameters

Type	Name	Description
System.Byte*	data
System.Int32	index
System.Byte	value

SetDataQBit(Byte*, Int32, Byte)

Declaration

public static void SetDataQBit(byte *data, int index, byte value)

Parameters

Type	Name	Description
System.Byte*	data
System.Int32	index
System.Byte	value

SetDataUInt16(UInt16*, Int32, UInt16)

Declaration

public static void SetDataUInt16(ushort *data, int index, ushort value)

Parameters

Type	Name	Description
System.UInt16*	data
System.Int32	index
System.UInt16	value

SetDataUInt32(UInt32*, Int32, UInt32)

Declaration

public static void SetDataUInt32(uint *data, int index, uint value)

Parameters

Type	Name	Description
System.UInt32*	data
System.Int32	index
System.UInt32	value