ImageGear v26.3 - Updated
ImageGear.Core Assembly / ImageGear.Processing Namespace / ImGearRasterProcessing Class / ConvertColorSpace Method / ConvertColorSpace(ImGearRasterPage,ImGearColorSpace,Boolean,ImGearPixel) Method
Image to change color space.
New color space.
Flag indicating whether to change pixel values according to the new color space.
Background to composite the image over when removing alpha channel.




In This Topic
    ConvertColorSpace(ImGearRasterPage,ImGearColorSpace,Boolean,ImGearPixel) Method
    In This Topic
    Converts page to a new color space, using the specified background color for images that contain Alpha channel, or allowing to skip pixel data conversion.
    Syntax
    'Declaration
     
    Public Overloads Shared Sub ConvertColorSpace( _
       ByVal page As ImGearRasterPage, _
       ByVal newColorSpace As ImGearColorSpace, _
       ByVal doNotScalePixels As Boolean, _
       ByVal backgroundColor As ImGearPixel _
    ) 
    'Usage
     
    Dim page As ImGearRasterPage
    Dim newColorSpace As ImGearColorSpace
    Dim doNotScalePixels As Boolean
    Dim backgroundColor As ImGearPixel
     
    ImGearRasterProcessing.ConvertColorSpace(page, newColorSpace, doNotScalePixels, backgroundColor)
    public static void ConvertColorSpace( 
       ImGearRasterPage page,
       ImGearColorSpace newColorSpace,
       bool doNotScalePixels,
       ImGearPixel backgroundColor
    )
    public: static void ConvertColorSpace( 
       ImGearRasterPage* page,
       ImGearColorSpace newColorSpace,
       bool doNotScalePixels,
       ImGearPixel* backgroundColor
    ) 
    public:
    static void ConvertColorSpace( 
       ImGearRasterPage^ page,
       ImGearColorSpace newColorSpace,
       bool doNotScalePixels,
       ImGearPixel^ backgroundColor
    ) 

    Parameters

    page
    Image to change color space.
    newColorSpace
    New color space.
    doNotScalePixels
    Flag indicating whether to change pixel values according to the new color space.
    backgroundColor
    Background to composite the image over when removing alpha channel.
    Remarks

    If conversion removes the alpha channel from an image, the image is composited over a solid background specified by BackColor. BackColor should be in the same color space as the original image, but without the Alpha channel. For example, if original image is in RGBA color space and newColorSpace is CMYK, BackColor should have RGB color space. The method will first transform the image into RGB and then to CMYK.

    The following formula is used to burn alpha (i.e., to convert from RGBA/P to RGB):

    • If Page is not pre-multiplied: I = I * A + B (1-A)
    • If Page is pre-multiplied: I = I + B (1-A)

    If the image contains extra channels, and newColorSpace contains extra channels, the method does not change them.

    Note: Conversion to Grayscale colorspace takes into account the human eye's sensitivity to different parts of the light spectrum. ImageGear uses the following formula when converting from RGB to Grayscale: Gray = Gray = Red * 77 / 255 + Green * 151 / 255 + Blue * 28 / 255.
    See Also