Introduction to Image Processing: Goals, Applications, and Perception
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This chapter delves into the fundamental aspects of image processing, highlighting its significance in enhancing pictorial information for human interpretation and enabling autonomous machine perception. The discussion includes related areas such as computer graphics and computer vision, alongside applications like image analysis, restoration, enhancement, and compression. Furthermore, it examines different types of images, image formats, and the nuances of human and machine visual perception. Understanding these components is essential for anyone entering the field of image processing.
Introduction to Image Processing: Goals, Applications, and Perception
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Presentation Transcript
Goals of Image Processing • “One picture is worth more than a thousand words” • Improvement of pictorial information for human interpretation. • Processing of scene data for autonomous machine perception.
Related Areas of Image Processing • Image Processing: image image • Computer Graphics: information image • Computer Vision: image information
Applications of Image Processing • Image Analysis • Image Restoration • Image Enhancement • Image Compression
Quantization False contours
Storage requirement A MxN image with 2k gray scales # of storage bits = M x N x k
Example Generally, transmission is accomplished in packets consisting of a start bit, a byte of information, and a stop bit. Using this approach, how many seconds would it take to transmit a 1024x1024 image with 256 gray levels at 300 baud (bits/sec)?
Types of Images • Analog Image • Digital Image • Binary Image • Gray-scale Image • Color Image • Multispectral Image
Image Formats • Vector Image • Bitmap Image • RAW no header • RLE (Run-Length Encoding) • PGM,PPM,PNM (Portable Gray Map) • GIF (Graphics Interchange Format) no more than 256 colors • TIF (Tag Image File Format) Scanner • EPS (Encapsulated Postscript) Printer • JPEG (Joint Photographic Experts Group) Compression ratio • MPEG (Motion Picture Experts Group) Video
Perception of objects • The spectrum (energy) of light source. • The spectral reflectance of the object surface. • The spectral sensitivity of the sensor (eye or camera).
How do we see an object? Light Eye Object • Luminance Lightness Rods • Chrominance Color Cones Human eye is more sensitive to luminance than to chrominance
Spatial & Temporal Resolution • Spatial resolution: 4-50 cycles per degree • Temporal resolution: 50 cycles per second • Brightness resolution: 100 gray levels
RGB Model • Color measurement: • A mixture of red, green, and blue light • Values between 0.0 (none) and 1.0 (lots) • Color examples • Red Green Blue • White 1.0 1.0 1.0 • Black 0.0 0.0 0.0 • Yellow 1.0 1.0 0.0 • Magenta 1.0 0.0 1.0 • Cyan 1.0 1.0 0.0
rgb Model(Normalized RGB) r+g+b=1
YIQ Model • TV transmission digital space YCBCR • analog space YIQ (NTSC) • YUV (PAL)