# CalGrayColorSpace Class

> A calibrated gray color space.

- Product: Adobe PDF Library 21
- Language: Modern C++
- Version: 21.4.0
- HTML page: https://docs.datalogics.com/apdfl21/ModernCPP/21.4.0/class/CalGrayColorSpace
- Version index: https://docs.datalogics.com/apdfl21/ModernCPP/21.4.0/llms.txt

```cpp
class CalGrayColorSpace : ColorSpace
```

**Namespace:** `datalogics_interface`

**Inherits from:** [`ColorSpace`](https://docs.datalogics.com/apdfl21/ModernCPP/21.4.0/class/ColorSpace.md)

## Description

A calibrated gray color space.

A CalGray color space is a special case of a single-component CIE-based color space, known as a CIE-based A color space.

This type of space is the one-dimensional (and usually achromatic) analog of CIE-based ABC spaces.

**Uses types:** [`PDFObject`](https://docs.datalogics.com/apdfl21/ModernCPP/21.4.0/class/PDFObject.md)

## Constructors

### CalGrayColorSpace

```cpp
datalogics_interface::CalGrayColorSpace::CalGrayColorSpace(const std::vector< double > &white_point)
```

*constructor*

**Parameters**

- `white_point` (`const std::vector< double > &`): An array of three numbers specifying the tristimulus value, in the CIE 1931 XYZ space, of the diffuse white point. The numbers X and Z must be positive, and Y must be equal to 1.0.

Create a CalGray color space.

### CalGrayColorSpace

```cpp
datalogics_interface::CalGrayColorSpace::CalGrayColorSpace(const std::vector< double > &white_point, const std::vector< double > &black_point, double gamma)
```

*constructor*

**Parameters**

- `white_point` (`const std::vector< double > &`): An array of three numbers specifying the tristimulus value, in the CIE 1931 XYZ space, of the diffuse white point. The numbers X and Z must be positive, and Y must be equal to 1.0.
- `black_point` (`const std::vector< double > &`): An array of three numbers specifying the tristimulus value, in the CIE 1931 XYZ space, of the diffuse black point. All three of these numbers must be non-negative.
- `gamma` (`double`): A number G defining the gamma for the gray component. G must be positive and is generally greater than or equal to 1.

Create a CalGray color space.

## Methods

### get_black_point

```cpp
std::vector< double > datalogics_interface::CalGrayColorSpace::get_black_point() const
```

**Returns:** `std::vector< double >`

An array of three numbers specifying the tristimulus value, in the CIE 1931 XYZ space, of the diffuse black point. All three of these numbers must be non-negative.

### get_gamma

```cpp
double datalogics_interface::CalGrayColorSpace::get_gamma() const
```

**Returns:** `double`

A number G defining the gamma for the gray component. G must be positive and is generally greater than or equal to 1.

### get_name

```cpp
std::string datalogics_interface::ColorSpace::get_name() const
```

**Returns:** `std::string`

The name of the color space. A named color space may be named something like DeviceRGB. More complicated color spaces may have a name like Indexed or ICCBased.

### get_num_components

```cpp
int datalogics_interface::ColorSpace::get_num_components() const
```

**Returns:** `int`

The number of color components.

The number of components in the color space.

For example, DeviceGray has 1 component, DeviceRGB has 3, and DeviceCMYK has 4.

### get_pdf_object

```cpp
std::unique_ptr< PDFObject > datalogics_interface::ColorSpace::get_pdf_object() const
```

**Returns:** [`std::unique_ptr< PDFObject >`](https://docs.datalogics.com/apdfl21/ModernCPP/21.4.0/class/PDFObject.md)

The PDFObject associated with the color space.

Get the PDFObject associated with the color space. This may be a PDFName, PDFDict, PDFStream, or PDFArray.

### get_white_point

```cpp
std::vector< double > datalogics_interface::CalGrayColorSpace::get_white_point() const
```

**Returns:** `std::vector< double >`

An array of three numbers specifying the tristimulus value, in the CIE 1931 XYZ space, of the diffuse white point. The numbers X and Z must be positive, and Y must be equal to 1.0.

### operator==

```cpp
virtual bool datalogics_interface::ColorSpace::operator==(const ColorSpace &other) const
```

**Parameters**

- `other` ([`const ColorSpace &`](https://docs.datalogics.com/apdfl21/ModernCPP/21.4.0/class/ColorSpace.md)): The ColorSpace to compare against.

**Returns:** `bool`

true if the two color spaces are equal, false otherwise.

Test for equality.

This works best for named color spaces.

More complex color spaces (such as ICCBased) do not support equality testing and will always return false.

### to_string

```cpp
std::string datalogics_interface::ColorSpace::to_string() const
```

**Returns:** `std::string`

A string describing this ColorSpace.

Convert a ColorSpace to a string representation.