FxImage.h

Introduction

Defines the FxImage class.

Classes

FxImage

The parent class of FxBitmap and FxTexture.

Typedefs

Structure that defines the parameters of an image.

typedef struct { 
    UInt32 width; 
    UInt32 height; 
    UInt32 depth; 
    UInt32 activeChannels; 
    FxImageType imageType; 
    FxImageOrigin origin; 
    FxPixelFormat pixelFormat; 
    BOOL isPremultiplied; 
    double pixelAspect; 
} FxImageInfo;  

Fields

width

The width of the image in pixels.

height

The height of the image in pixels.

depth

The depth of each pixel component. Must be 8 for UInt8, 16 for float 16, or 32 for float 32.

activeChannels

The number of channels in the image. Should always be 4.

imageType

The type (bitmap or texture) of the image.

origin

The orientation of the image's coordinate system (top-down or bottom-up).

pixelFormat

The format of each pixel (ARGB, RGBA, r408, or r4fl).

isPremultiplied

YES if the RGB values are premultiplied by the alpha. Should always be YES.

pixelAspect

The ratio of the width of each pixel to its height (e.g. 1.0 = Square Pixel, 0.9 = NTSC DV, etc.).

Discussion

The FxImageInfo structure describes an image and is used to create a new image. If the pixelFormat is kFxImageType_R408, then the depth must be 8. If kFxImageType_R4fl, then the depth must be 32.

Enumerations

enum { 
    kFxImageColorInfo_RGB_LINEAR = 0, 
    kFxImageColorInfo_RGB_GAMMA_DEFAULT_MACINTOSH_DISPLAY, 
    kFxImageColorInfo_RGB_GAMMA_VIDEO, 
    kFxImageColorInfo_YCbCr_R601, 
    kFXImageColorInfo_YCbCr_R709 
};  

Constants

kFxImageColorInfo_RGB_LINEAR

RGB linear (not gamma corrected)

kFxImageColorInfo_RGB_GAMMA_DEFAULT_MACINTOSH_DISPLAY

RGB at the default gamma for Macintosh displays (1.8)

kFxImageColorInfo_RGB_GAMMA_VIDEO

RGB at video gamma (2.2)

kFxImageColorInfo_YCbCr_R601

YCbCr with Rec. 601 color matrix and gamma curve

KFXImageColorInfo_YCbCr_R709

YCbCr with Rec. 709 color matrix and gamma curve

Discussion

Identifies some color properties of an FxImage. These include the color space, gamma level, and, in the case of YCbCr images, the color matrix for conversion to RGB.

enum { 
    kFxImageOrigin_BOTTOM_LEFT = 0, 
    kFxImageOrigin_TOP_LEFT = 2 
};  

Constants

kFxImageOrigin_BOTTOM_LEFT

Right-handed "bottom-up" coordinate system where Y values increase upwardly.

kFxImageOrigin_TOP_LEFT

Left-handed "top-down" coordinate system where Y values increase downwardly.

Discussion

Identifies the orientation of an image's coordinate system. Images in Motion have a bottom-left origin. Images in Final Cut have a top-left origin.

enum { 
    kFxImageType_UNKNOWN = 0, 
    kFxImageType_BITMAP = 1, 
    kFxImageType_TEXTURE = 2 
};  

Constants

kFxImageType_UNKNOWN

Unknown image type. (You should never encounter this.)

kFxImageType_BITMAP

RAM-based bitmap image.

kFxImageType_TEXTURE

OpenGL-based texture image.

Discussion

Identifies the type of an image.

enum { 
    kFxPixelFormat_RGBA = 0, 
    kFxPixelFormat_ARGB = 2, 
    kFxPixelFormat_R408 = 4, 
    kFxPixelFormat_R4fl = 5 
};  

Constants

kFxPixelFormat_RGBA

RGB+A pixels with component order R,G,B,A.

kFxPixelFormat_ARGB

RGB+A pixels with component order A,R,G,B.

kFxPixelFormat_R408

8-bit YUV+A pixels with component order A,Y,U,V in the 'r408' format.

kFxPixelFormat_R4fl

32-bit float YUV+A pixels with component order A,Y,U,V, in the 'r4fl' format.

Discussion

Identifies the format of the pixels for an image.

NOTES:

The r408 pixel format is only valid if the depth is 8 bits. The r4fl pixel format is only valid if the depth is 32 bits.

An FxPlug will only be given YUV pixels if it has declared that it supports either the r408 or r4fl compatible.

The r408 and r4fl formats are detailed in Letters from the Ice Floe #27 on the Apple Developer website.

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Last Updated: 2008-06-05