tailieunhanh - Lecture Steganography: Digital image - Ho Dac Hung

Lecture Steganography: Digital Image Formats has contents such as Color representation, Spatial-domain formats, and Transform-domain formats. Download this lecture to see more. | Digital Image Formats Ho Dac Hung 1 Contents Color representation Spatial-domain formats Transform-domain formats 2 1. Color Representation Visible light is a superposition of electromagnetic waves with wavelengths spanning the interval between approximately 380 nm and 750 nm. Each color can be associated with the spectral density function P λ which describes the amount of energy present at wavelength λ. 3 1. Color Representation 4 1. Color Representation Denoting the amount of each color as R G and B where each number is from the interval 0 1 zero intensity to full intensity each color can be represented as a three- dimensional vector in the RGB color cube R G B 0 1 3. Hardware systems that emit light are usually modeled as additive. 5 1. Color Representation The subtractive color model is used for hardware devices that create colors by absorption of certain wavelengths rather than emission of light. 6 1. Color Representation The standard basic colors for subtractive systems are by convention cyan magenta and yellow leading to color representation using the vector CMY. These three colors are obtained by removing from white the colors red green and blue respectively. C 1 R M 1 G Y 1 B. 7 1. Color Representation A very popular color system is the YUV model originally developed for transmission of color TV signals. The requirement of backward compatibility with old black-andwhite TVs led the designers to form the color TV signal as luminance augmented with chrominance signals. 8 1. Color Representation The luminance Y is defined as a weighted linear combination of the RGB channels with weights determined by the sensitivity of the human eye to the three RGB colors Y 9 1. Color Representation The chrominance components are the differences conveying the color information U R Y V B Y 10 1. Color Representation 1 1 0 1 1 0 1 11 1. Color Representation 0 128

• An ninh - Bảo mật
• Lecture of Steganography
• Bài giảng Kỹ thuật giấu tin
• Digital Image Formats
• Color representation
• Spatial domain formats
• Transform domain formats
• Lecture naive steganography
• Lecture LSB embedding
• Steganography in palatte images
• Steganographic channels
• Steganography by cover selection
• Steganography by cover synthesis
• Steganography by cover modification
• The crypto systems
• Steganography throughout history
• Modern steganography
• Lecture of terminology
• Lecture watermarking principles
• The watermarking applications
• Lecture audio watermarking
• Content authentication applications
• Transparency attacks and algorithms
• Host locations in Ccver
• The Choice of a Workspace
• Discrete fourier transform