1、【简答题】please give the classification of medium from itu?
2、【简答题】for each of the following tasks specify the best file type to be used if the actions given below are carried out on the internet. action: downloading cd-quality audio displaying a photo gallery of real world images displaying animated banners with text
1.4main properties of a multimedia system.
1、【简答题】please describe the main properties of multimedia system.
1.5hypermedia and multimedia
1、【填空题】http is a _____ that was originally designed for transmitting hypermedia, but can also support the transmission of any file type.
2、【简答题】what is hypermedia?
2.1sound and signal
1、【填空题】two general classes of signals can be identified as _______ and _________.
2.2sampling
1、【单选题】in general, the higher quality of the audio requires ( ) a、the lower sample levels and sampling frequency b、the higher sample levels and sampling frequency c、the lower sample levels and higher sampling frequency d、the higher sample levels and lower sampling frequency
2、【单选题】which of the following best describes the process known as ‘sampling’ in multimedia technology a、conversion of analog audio data to digital audio data b、conversion of analog video data to digital video data c、obtaining discrete signals from an analog input signal d、obtaining discrete measurements of an analog signal and storing it as discrete values. e、none of the above
3、【填空题】the rate at which a continuous waveform is sampled is called the ______.
2.3 quantization
1、【简答题】the rate at which a continuous waveform is sampled is called the ________. it is measured in__________.
2、【简答题】the resolution or quantization of a sample value depends on the number of bits used in measuring the height of the waveform. a 16-bit quantization results in _____________ possible values.
2.4audio digitization
1、【填空题】cd-quality audio is generated if it operates at _______ samples per second with a ______bit liner pcm encoded quantization.
2.6bit rates of digital sequence
1、【简答题】assuming the bandwidth of a speech signal is from 50hz through to 10khz and that of a music signal is from 15hz through to 20khz, derive the bit rate that is generated by the digitization procedure in each case. assuming the nyquist sampling rate is used with 12 bits per sample for the speech signal and 16 bits per sample for the music signal. derive the memory required to store a 10 minutes passage of stereophonic music.
2.7coding method
1、【简答题】explain the principles of adpcm.
3.1fundamental of colors
1、【判断题】all digital images are stored in the computer as pixels.
2、【判断题】a vector image can not be transformed into a bitmapped image.
3.2basic concepts of images
1、【判断题】1-bit is capable of displaying 2 color.
2、【简答题】1. what is “y” and “u/v” in the yuv color model ?
3、【简答题】are the rgb and cmyk color models “additive mixing” or “subtractive mixing”? why?
3.3digital image properties
1、【填空题】a 5×6 inch photograph when scanned at 200dpi will result in an image which is ________ pixels.
2、【简答题】what is the definition of aspect ratio of a display screen?
3、【简答题】what is color depth?
3.72-d dft
1、【简答题】
3.10image restoration
1、【简答题】
2、【简答题】
3、【简答题】
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4.1 basics of digital video
1、【填空题】there are three different types of video signals, and they are __________, __________ and __________.
2、【填空题】higher-end video systems make use of three separate video signals for the __________, __________, and __________ image planes.
3、【填空题】for composite video, color (“chrominance") and intensity (‘luminance") signals are mixed into __________.
4、【填空题】for s-video, as a compromise, (separated video, or super-video, e.g., in s-vhs) uses two wires, one for__________ and another for __________.
5、【填空题】an analog signal f(t) samples a __________ image. so called “progressive” scanning traces through a complete picture (a frame) row-wise for each time interval.
4.2digital video
1、【填空题】pal (__________) is a tv standard widely used in western europe, china, india, and many other parts of the world.
2、【填空题】pal uses __________scan lines per frame, at __________frames/second, with a __________aspect ratio and interlaced fields.
3、【填空题】the meaning of j:a:b j: __________________________________________________________________________________________ a: __________________________________________________________________________________________ b: __________________________________________________________________________________________
4、【填空题】for video, __________ is chosen as the compression standard. for audio, __________ is chosen as the compression standard.
5、【填空题】hdtv is short for ____________________.
5.1multimedia data compression technology
1、【填空题】__________ are used when raw image data are difficult to obtain or contain vital information that may be destroyed by compression, e.g. in medical diagnostic imaging.
2、【填空题】__________ can be used when raw image data can be easily reproduced or when the information loss can be tolerated at the receiver site, e.g. in digital television, teleconferencing.
3、【填空题】the objective of image compression is to ________________________________________.
4、【填空题】compression ratio cr=__________
5、【填空题】the relative data redundancy rd of the first data set (the one characterized by n1 ) can be defined as rd=__________
6、【填空题】a compression system consists of two distinct structural blocks: __________ and __________.
5.2elements of information theory
1、【填空题】——is the measurement of the average information in an image.
5.3huffman coding
1、【填空题】the huffman coding is the most popular technique to ____________________.
2、【填空题】the limitations of huffman coding is that ____________________ and ____________________.
3、【填空题】when coding the symbols of an information source individually, huffman coding yields the __________ possible number of code symbols per source symbol.
4、【填空题】the huffman algorithm find ____________________ for the image by finding the histogram order the __________ (histogram magnitudes) from smallest to largest combine the __________ two by addition goto step 2, until only __________ are left by working backward along the tree, generate code by alternating assignment of 0 and 1
5、【填空题】the average code length for an information source s is strictly less than __________.
5.4arithmetic coding
1、【填空题】__________ transforms input data into a single floating point number between 0 and 1.
2、【填空题】arithmetic coding uses the __________ (histogram), so it can theoretically achieve the maximum compression specified by the entropy.
3、【填空题】it works by successively subdividing the interval between 0 and 1, based on the placement of the __________ in the probability distribution.
4、【填空题】the way to calculate the range of source symbol: low=____________________. high=____________________ (the first range is set to 1.)
5、【填空题】in the decoding part, we use the formula ____________________ to take the source symbol.
5.5lossless predictive coding
1、【填空题】the purpose of __________ is to eliminate the interpixel redundancies of closely spaced pixels by extracting and coding only the new information in each pixel.
2、【填空题】the new information of a pixel is defined as the difference between the __________ and __________ value of that pixel.
3、【填空题】2d prediction is a function of the previous pixels in a__________, __________ scan of an image.
4、【填空题】the principal difference between lossless and lossy compression is the __________ or __________ of the quantizer.
5.6transform coding
1、【填空题】transform coding means that a __________ linear transform (klt、 dft、dct、wht、….) is used to map the image into a set of __________.
2、【填空题】for most natural images, a significant number of the coefficients have __________ magnitudes and can be coarsely quantized (or discarded entirely) with __________ image distortion.
3、【填空题】adaptive transform coding means all of the transform encoding steps can be adapted to __________.
4、【填空题】the choice of a particular transform depends on the amount of ____________________ and ____________________ available.
5.7jpeg standard
1、【填空题】jpeg is short for iso/iec ____________________.
2、【填空题】for jpeg compression ratios, 30:1 to 50:1 compression is possible with small to moderate defects, 100:1 compression is quite feasible for __________ purposes.
3、【填空题】dc component of a block is large and varied, but often close to the dc value of the __________.
4、【填空题】encode the __________ of dc component from previous 8x8 blocks using ____________________ (dpcm).
5、【填空题】zigzag scan maps an 8x8 block into a __________ vector, and zigzag pattern groups low frequency coefficients in top of vector.
5.8mpeg video coding and compression
1、【填空题】mpeg is short for iso ______________________________.
2、【填空题】mpeg-1 is a standard for __________ compression of video and audio.
3、【填空题】mpeg-1 is designed to compress vhs-quality raw digital video and cd audio down to __________ mbit/s (26:1 and 6:1 compression ratios respectively) without____________________.
4、【填空题】an mpeg stream consists of 3 types of frames: i (__________), p (__________), b (__________).
5、【填空题】motion vector tries to match each block in the actual picture to content in the previous picture. matching is made by shifting each of the _____x_____ blocks of the two successive pictures pixel by pixel each direction.
5.9mpeg audio compression
1、【填空题】__________ is based on masking properties of the human ear: during strong sounds, you do not hear the weakest sounds.
2、【填空题】mpeg audio compression takes advantage of__________ constructing a large multi-dimensional lookup table to transmit masked frequency components using fewer bits.
3、【填空题】temporal masking tells us that after a loud sound, there is a __________ before we can hear a soft sound.
4、【填空题】frequency masking tells us that if a stronger sound and nearby weaker sound compete, you cannot hear the __________.
5、【填空题】at low frequencies, we cannot detect ____________________ because of stereo redundancy.
5.10mpeg 2 standard
1、【填空题】mpeg-2 is a standard for“the generic coding of __________ and associated audio information”.
2、【填空题】mpeg-2 describes a combination of __________ and __________ methods which permit storage and transmission of movies using currently available storage media and transmission bandwidth.
3、【填空题】mpeg-2 defined seven __________ aimed at different applications: simple, main, snr scalable, spatially scalable, high, 4:2:2, multiview.
4、【填空题】the dvd video specification allows only four __________: 720*480, 704*480, 352*480, and 352*240
5、【填空题】there are five scalability types: ____________________, ____________________, ____________________, ____________________, ____________________.
5.11mpeg 4 standard
1、【填空题】mpeg-4: a newer standard. besides compression, plays great attention to issues about __________.
2、【填空题】mpeg-4 departs from its predecessors in adopting a new __________ coding: offering higher __________, and mpeg-4 videos can be composed and manipulated by simple operations on the visual objects.
3、【填空题】__________ is currently one of the leading candidates to carry high definition tv (hdtv) video content on many potential applications.
4、【填空题】vlc-based entropy decoding: two entropy methods are used in the variable-length entropy decoder: __________ (uvlc) and__________ (cavlc).
5、【填空题】the main profile contains all baseline profile features (except aso, fmo, and redundant slices) plus the following: ____________________, ____________________, ____________________.
5.12mpeg-1 audio
1、【填空题】he general encoding process is____________________, ____________________, ____________________, ____________________, ____________________.
2、【填空题】mpeg has __________ layers, and __________ is the most complex one, and was originally aimed at audio transmission over isdn lines.
3、【填空题】most of the complexity increase is at the __________, not the decoder ---- accounting for ____________________.
4、【填空题】stereo redundancy coding has 4 modes: ____________________, ____________________, ____________________, ____________________.
5、【填空题】mpeg approach to compression relies on: __________ and human auditory system is not __________ within the width of a critical band (perceived loudness and audibility of a frequency)
7.1content-based multimedia retrieval
1、【填空题】low-level visual content’s features includes__________, __________, __________, __________, while semantic contents’ feature is high-level concepts such as objects and events.
2、【填空题】to facilitate fast and accurate content access to video data, we should segment a video document into __________ and __________.
3、【填空题】content-based video retrieval is the process of attaching content based __________ to video shots and is essential for content-based classification and retrieval.
4、【填空题】methods to query content-based video include ____________________, ____________________, ____________________, ____________________, ____________________ and concept query (query by keyword).
5、【填空题】the limitation of qbe includes____________________, ____________________ and ____________________.
7.2four processes
1、【填空题】four processes involved by video-content analysis and indexing are____________________, ____________________, ____________________ and ____________________.
2、【填空题】for feature extraction, the effectiveness of an indexing scheme depends on the effectiveness of __________ in content presentation.
3、【填空题】structure analysis is the process of extracting ____________________ of video sequences or programs.
4、【填空题】video abstraction is the process of creating a presentation of __________ about a landscape or the structure of video, which should be much __________ than the original video.
5、【填空题】__________: involve the user in a loop, whereby images retrieved are used in further rounds of convergence onto correct returns
7.3cbir
1、【填空题】cbir is the process of __________ images from a collection on the basis of __________ (such as color, texture and shape) automatically extracted from the images themselves.
2、【填空题】queries can be specified in two different ways ____________________ and ____________________.
3、【填空题】query predicates include ____________________, ____________________ and ____________________.
4、【填空题】attribute predicates concern the __________ for which an exact value is supplied for each object and take __________ retrieval.
5、【填空题】structural predicates concern the structure of __________ and it can be answered by __________ and information about the __________.
6、【填空题】semantic predicates concern the __________ content of the required data, depending on the features that have been extracted and stored for each __________.
7.4query expressions
1、【填空题】the ways to specify the degree of relevance of the retrieved objects include ______________________________, ______________________________, ______________________________.
2、【填空题】for using some imprecise terms and predicates, it represents a set of possible acceptable values with respect to which the __________ or the __________ has to be matched.
3、【填空题】the corresponding query is executed by assigning some __________ and __________ values to each predicate and term.
4、【填空题】the histogram of image i is defined as: for a color ci, hci(i) represents the number of __________ of color ci in image i. or: for any pixel in image i, hci(i) represents the __________ of that pixel is in color ci.
5、【填空题】most commercial cbir systems include __________ as one of the features (e.g., qbic of ibm).