# GrayscaleBitmap ## Content [**DsPdfJS API v9.1.3**](../README) *** [DsPdfJS API](../globals) / GrayscaleBitmap # Class: GrayscaleBitmap Represents a grayscale image or transparency mask with 8 bits per pixel. ## Extends - [`ObjectBase`](ObjectBase) ## Constructors ### Constructor > **new GrayscaleBitmap**(`width`, `height`, `gbProperties?`): `GrayscaleBitmap` Creates a GrayscaleBitmap instance with optionally initialized pixels. #### Parameters ##### width `number` The grayscale bitmap width, in pixels. ##### height `number` The grayscale bitmap height, in pixels. ##### gbProperties? [`GrayscaleBitmapProperties`](../type-aliases/GrayscaleBitmapProperties) The settings for creating a grayscale bitmap. #### Returns `GrayscaleBitmap` #### Overrides `ObjectBase.constructor` ### Constructor > **new GrayscaleBitmap**(`om`, `width`, `height`, `gbProperties?`): `GrayscaleBitmap` Creates a GrayscaleBitmap instance with optionally initialized pixels. #### Parameters ##### om [`ObjectManager`](ObjectManager) An object manager that controls the lifetime of the GrayscaleBitmap object. ##### width `number` The grayscale bitmap width, in pixels. ##### height `number` The grayscale bitmap height, in pixels. ##### gbProperties? [`GrayscaleBitmapProperties`](../type-aliases/GrayscaleBitmapProperties) The settings for creating a grayscale bitmap. #### Returns `GrayscaleBitmap` #### Overrides `ObjectBase.constructor` ## Accessors ### height #### Get Signature > **get** **height**(): `number` Gets the height of the GrayscaleBitmap, in pixels. ##### Returns `number` *** ### id #### Get Signature > **get** **id**(): `number` Gets the reference to the object. ##### Returns `number` #### Inherited from [`ObjectBase`](ObjectBase).[`id`](ObjectBase#id) *** ### om #### Get Signature > **get** **om**(): [`ObjectManager`](ObjectManager) Gets the owner [ObjectManager](ObjectManager) instance. ##### Returns [`ObjectManager`](ObjectManager) #### Inherited from [`ObjectBase`](ObjectBase).[`om`](ObjectBase#om) *** ### transparencyMask #### Get Signature > **get** **transparencyMask**(): `boolean` Gets or sets a value indicating whether the image is used to define an alpha mask of another image. ##### Returns `boolean` #### Set Signature > **set** **transparencyMask**(`value`): `void` Gets or sets a value indicating whether the image is used to define an alpha mask of another image. ##### Parameters ###### value `boolean` ##### Returns `void` *** ### whiteIsZero #### Get Signature > **get** **whiteIsZero**(): `boolean` Gets or sets a value specifying whether 0 represents white and 255 represents black (if true) or vice versa (if false). ##### Returns `boolean` #### Set Signature > **set** **whiteIsZero**(`value`): `void` Gets or sets a value specifying whether 0 represents white and 255 represents black (if true) or vice versa (if false). ##### Parameters ###### value `boolean` ##### Returns `void` *** ### width #### Get Signature > **get** **width**(): `number` Gets the width of the GrayscaleBitmap, in pixels. ##### Returns `number` ## Methods ### adjustLevels() > **adjustLevels**(`blackPoint`, `whitePoint`, `outputBlack`, `outputWhite`, `midtone?`): `void` Adjusts the levels of an image histogram. The method maps the input range of values (blackPoint..whitePoint) to the output range (outputBlack..outputWhite) using the specified gamma correction (midtone). #### Parameters ##### blackPoint `number` The input black point (between 0 and 255). ##### whitePoint `number` The input white point (between 0 and 255). ##### outputBlack `number` The output black point (between 0 and 255). ##### outputWhite `number` The output white point (between 0 and 255). ##### midtone? `number` = `1.0` The value of gamma correction. #### Returns `void` *** ### applyGaussianBlur() > **applyGaussianBlur**(`radius?`, `borderMode?`, `borderColor?`): `void` Applies a Gaussian blur to this GrayscaleBitmap. #### Parameters ##### radius? `number` = `9` The radius of the blur, in pixels. ##### borderMode? The mapping mode for the pixels outside of the border, "RepeatEdge" if null. [`GaussianBlurBorderMode`](../enumerations/GaussianBlurBorderMode) | `null` ##### borderColor? `number` = `0` The color used to blend with the edge pixels of the image (between 0 and 255). #### Returns `void` *** ### applyGlow() > **applyGlow**(`infRadius?`, `blurRadius?`): `void` When applied to a grayscale mask built from a color image using the [Bitmap#toGrayscaleBitmap](Bitmap#tograyscalebitmap) method, modifies it so that the result can be used as a transparency mask to produce "Glow" or "Soft Edges" effects. #### Parameters ##### infRadius? `number` = `4` The radius of inflation (positive, glow) or deflation (negative, soft edges), in pixels. ##### blurRadius? `number` = `6` The radius of Gaussian blur, in pixels. #### Returns `void` *** ### autoContrast() #### Call Signature > **autoContrast**(): `void` Modifies pixel intensities such that available range of values (0..255) is fully covered. ##### Returns `void` #### Call Signature > **autoContrast**(`lowClipFraction`, `highClipFraction`): `void` Modifies pixel intensities, clipping extremely low and extremely high values, such that available range of values (0..255) is fully covered. ##### Parameters ###### lowClipFraction `number` The fraction of extremely low values to be clipped, not greater than 0.1. ###### highClipFraction `number` The fraction of extremely high values to be clipped, not greater than 0.1. ##### Returns `void` *** ### clear() > **clear**(`value`, `bounds?`): `void` Clears the GrayscaleBitmap with the specified value. #### Parameters ##### value `number` The value (between 0 and 255) to fill the image. ##### bounds? The target rectangle of the GrayscaleBitmap. [`Bounds`](../type-aliases/Bounds) | `null` #### Returns `void` *** ### clip() #### Call Signature > **clip**(`x`, `y`, `width`, `height`, `metadataOnly?`): `GrayscaleBitmap` Creates a new GrayscaleBitmap with a fragment of the image. ##### Parameters ###### x `number` The X coordinate of the clipping rectangle. ###### y `number` The Y coordinate of the clipping rectangle. ###### width `number` The width of the clipping rectangle. ###### height `number` The height of the clipping rectangle. ###### metadataOnly? `boolean` Specifies whether to copy the image metadata only, not actual pixel data. The default is false. ##### Returns `GrayscaleBitmap` A new GrayscaleBitmap with a fragment of the source image. #### Call Signature > **clip**(`bounds`, `metadataOnly?`): `GrayscaleBitmap` Creates a new GrayscaleBitmap with a fragment of the image. ##### Parameters ###### bounds [`Bounds`](../type-aliases/Bounds) Clipping rectangle of the source image to be extracted as a new GrayscaleBitmap. ###### metadataOnly? `boolean` Specifies whether to copy the image metadata only, not actual pixel data. The default is false. ##### Returns `GrayscaleBitmap` A new GrayscaleBitmap with a fragment of the source image. *** ### clone() > **clone**(`metadataOnly?`): `GrayscaleBitmap` Creates a new GrayscaleBitmap with a copy of the image. #### Parameters ##### metadataOnly? `boolean` = `false` specifies whether to copy the image metadata only, not actual pixel data. #### Returns `GrayscaleBitmap` A new instance of the GrayscaleBitmap. *** ### free() > **free**(): `void` Detaches the object from the [ObjectManager](ObjectManager) and deallocates its memory, if possible. #### Returns `void` #### Inherited from [`ObjectBase`](ObjectBase).[`free`](ObjectBase#free) *** ### invertColors() > **invertColors**(): `void` Inverts the pixel colors from black to white and vice versa. #### Returns `void` *** ### rebind() > **rebind**(`omTo`): `void` Rebinds the object from the current [ObjectManager](ObjectManager) to the specified one. #### Parameters ##### omTo [`ObjectManager`](ObjectManager) The new [ObjectManager](ObjectManager) for the object. #### Returns `void` #### Inherited from [`ObjectBase`](ObjectBase).[`rebind`](ObjectBase#rebind) *** ### toBitmap() > **toBitmap**(): [`Bitmap`](Bitmap) Creates a [Bitmap](Bitmap) instance from the current GrayscaleBitmap. #### Returns [`Bitmap`](Bitmap) A new instance of the [Bitmap](Bitmap) class. *** ### toShadowBitmap() > **toShadowBitmap**(`shadowColor`, `opacityFactor?`, `zeroIsOpaque?`): [`Bitmap`](Bitmap) Creates a semi-transparent [Bitmap](Bitmap) from the current GrayscaleBitmap. This method treats the current GrayscaleBitmap as a transparency mask, regardless of the transparencyMask property value. #### Parameters ##### shadowColor [`Color`](../type-aliases/Color) The color to fill opaque pixels of the target bitmap. ##### opacityFactor? `number` = `1` Additional factor to scale the alpha channel. ##### zeroIsOpaque? `boolean` = `false` Specifies whether zero values correspond to fully opaque (true) or fully transparent (false) pixels. #### Returns [`Bitmap`](Bitmap) A new instance of the [Bitmap](Bitmap) class.