Image processing method and system
AssigneeBlackmagic Design Pty Ltd
InventorsCarsten Buettner, Rowan Douglas Habel
Life of this patent
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Abstract
A method of processing image data that is represented in a frequency domain includes the step of applying a noise signal to the image data to yield noise-applied image data. In at least one embodiment, the image data includes one or more sets of coefficients arising from application of a discrete cosine transform, each set of coefficients comprising a DC coefficient and one or more AC coefficients. The noise signal is applied to the image data by modifying one or more of the coefficients in one or more of the sets. The modifying includes replacing one or more of the AC coefficients with random or pseudo random numbers having a distribution. Noise present in the image data may be equalized, prior to the step of applying the noise signal.
Claims27
A method of processing video data, said video data comprising a sequence of image frames, each image frame comprising image data represented in a frequency domain, said image data comprising one or more sets of frequency domain coefficients, and each set of frequency domain coefficients comprising a DC coefficient and one or more AC coefficients, the method including:
- for each image frame of the video data, modifying one or more AC coefficients in one or more of the sets of frequency domain coefficients having a value of zero, by applying a noise signal to the zero-valued AC coefficients of the image data to yield noise-applied image data for playback of said video data.
A method for processing an image signal obtained from an image sensor, the image signal having a noise component with an amplitude and an image component with an amplitude, the method including:
- determining a conversion function from characteristics of the image sensor;
- and
- applying the conversion function to the image signal to yield a signal with a noise component of substantially constant amplitude independent of the amplitude of the image component.
A method of decoding video data for playback, said video data comprising a sequence of image frames, each image frame comprising quantized image data represented in a frequency domain, said method comprising:
- applying a noise signal to the image data to yield noise-applied image data;
- and
- decoding said noise-applied image data to enable playback of the video data, wherein at playback, image frames include noise that is perceptually similar to noise that was present in image frames prior to encoding.
An image processing device configured to decode video data for playback, said video data comprising a sequence of image frames, each image frame comprising quantized image data represented in a frequency domain, said quantized image data comprising one or more sets of coefficients arising from application of a mathematical transform, each set of coefficients comprising a DC coefficient and one or more AC coefficients, the image processing device being configured to:
- apply a noise signal to the quantized image data to yield noise-applied image data;
- decode said noise-applied image data, wherein the noise signal is selected such that decoding said noise-applied image data regenerates noise in said image frames that is perceptually similar to noise that was present in the image data prior to quantization.
Dependencies are inferred from the claim text.