still use the feature detection algorithm.
Each step involves a lot of algorithm research, focusing on mathematics, statistics, image coding, signal processing and other theories.
The following is a simple implementation of Ruan Yifeng:
If you enter a Google image URL or directly upload an image, Google will find a similar image. The following figure shows Alyson Hannigan, an American actress.
After the upload, Google returns the following results:
What is the principle of this
Search for similar images
Similar image search refers to how to calculate the similarity between two images. The key technology here is "perceptual hash algorithm ), it generates a "fingerprint" (fingerprint) string for each image, and then compares the fingerprints of different images. The closer the result is, the more similar the image is.
I. Perception Hash Algorithm
1. Reduce the size
Reduce the image size to 8x8, with a total of 64 pixels. Th
still use the feature detection algorithm.
Each step involves a lot of algorithm research, focusing on mathematics, statistics, image coding, signal processing and other theories.
The following is a simple implementation of Ruan Yifeng:
If you enter a Google image URL or directly upload an image, Google will find a similar image. The following figure shows Alyson Hannigan, an American actress.
After the upload, Google returns the following results:
What is the principle of this
-> private = keypad;Set_bit (ev_key, input_dev-> evbit); // press the keySet_bit (ev_rel, input_dev-> evbit); // key releasePxa3xx_keypad_build_keycode (keypad); // The device keyboard ing code.This function performs key-encryption settings based on the matrix_key_map in the pxa3xx_device_keypad device,Pxa_set_keypad_info ( jades_keypad_info) => Register jades_keypad_info as pdata;# Define max_matrix_key_num (8*8)Matrix_keycodes [max_matrix_key_num]; 8x8
Chapter 2 transform Encoding
1. Transform Encoding
Purpose of Transcoding
Remove spatial signal correlation
The capability of spatial signals is concentrated on a small part of the low frequency coefficient in the frequency domain.
Small coefficients can be quantified without seriously affecting the quality of reconstructed images.
Block and Global Transformations
Block transform: discrete cosine transform (discrete cosine transform, DCT), 4x4,
, if ABC is input, its combination includes a, B, c, AB, AC, BC, and ABC.
Extension 2: enter an array containing eight numbers to determine whether the eight numbers can be placed on the eight vertices of the cube, the sum of the four vertices on the opposite surface of the cube is equal.
--------------------------------------------------------------
Extended: Eight queens
Question: Eight queens are placed on 8x8 chess sets so that they cannot attack
into a line. Of course, do not select it. We want to press 480 p.Quant optionsTrellis:Trellis quantization. Find the appropriate quantization value for each 8x8 block. cabac is required. The default value is 0.0: Disable1: used only for the final Encoding2: Always Use(Improve quality and reduce speed. We recommend that you enable it .)Number of refence frames:Maximum number of reference frames, ranging from 0 ~ 16. The default value is 1 (the paramet
containing the lexicographically first path that visits all squares of the chessboard with knight moves followed by an empty line. the path shoshould be given on a single line by concatenating the names of the visited squares. each square name consists of a capital letter followed by a number.
If no such path exist, you shoshould output impossible on a single line.
Sample Input
31 12 34 3
Sample output
Scenario #1:A1Scenario #2:impossibleScenario #3:A1B3C1A2B4C2A3B1C3A4B2C4
The question is to
the row on the chessboard.
Output
For each test case, print one line saying "to get from xx to YY takes n knight moves .".
Sample inpute2 E4
A1 B2
B2 C3
A1 H8
A1 H7
H8 A1
B1 C3
F6 F6
Sample outputto get from E2 to E4 takes 2 knight moves.
To get from A1 to B2 takes 4 knight moves.
To get from B2 to C3 takes 2 knight moves.
To get from A1 to H8 takes 6 knight moves.
To get from A1 to H7 takes 5 knight moves.
To get from H8 to A1 takes 6 knight moves.
To get from B1 to C3 takes 1 knight moves.
To
foreground by default, and another color as the background. In this case, we connect the foreground pixel block by default (imagine a dotted line ). This rule calculates the two diagonal lines that can connect to the least grid to determine which diagonal lines to connect. For example, an 8x8 data center with a diagonal line is shown in Figure 4-. This rule connects the red diagonal lines in the middle, while the green lines do not. Because the two d
combination. Next we need to select M characters from the remaining n-1 characters. Both options are easily implemented using recursion. The following is a reference code for this idea:
# Include
Because the combination can be a combination of 1 character and 2 character ...... Until the combination of n characters, so in the Void combination (char * string) function, we need a for loop. In addition, we use a vector to store the characters that we choose to put into the combination.Method 2: b
, the length of the iend data block is always 0 (00 00 00, unless manually added? Information), the data ID is always iend (49 45 4E 44), so the CRC code is always AE 42 60 82.
Instance research PNG
The following is an image generated by fireworks. The image size is 8x8. To make it easier for you to watch, we can enlarge the image:
Use ultraedit32 to open the file, for example:00000000 ~ 00000007:
We can see that the selected first 8 bytes are the id
Ogg is a free and open standard container format maintained by the xiph. Org Foundation. The Ogg format is not restricted by software patents and is designed for efficient streaming media and high-quality digital multimedia processing.
Ogg refers to a file format that can be incorporated into a wide range of free and open source code codecs, including sound effects, video, text (like subtitles) and metadata processing.
Ogg theora
Theora is a premium-free and open-format lossy image compression t
/*************************************** * ******************************** // * Eight Queen's question, it is an ancient and famous question, and it is backtracking. Algorithm . /* This problem was raised by the famous mathematician Gauss in the 19th century in 1850:/* Eight queens were placed on 8x8 gags of chess, so that they could not attack each other, /* The two queens cannot be in the same row, column, or diagonal line. /***********************
: // select an algorithm for the macro module. The value ranges from 0 ~ 2 The default value is 0. The larger the value, the slower the conversion, but it is advantageous in terms of quality and file size.Mv0: // compile each macro module and select the best one. It is invalid when mbd is set to 0;Trell: // It will slightly increase the quality, and the effect of mbd> 0 is more obvious;V4mv: // quantum mesh search to find the optimal code for every 8x8
lattice.
Here, an 8x8 matrix is defined, and a letter C is displayed. the white square is represented by 0, and the black square is represented by 1, the code for these eight lines of images is:
Line
Binary representation
Hexadecimal representation
0
00000000
0x00
1
00111110
0x3E
2
01110000
0xE0
3
01110000
0xE0
4
01110000
0xE0
5
01110000
0xE0
6
00111110
0x3E
7
00000000
0x00
To output these points, you need to first draw the first line,
($ image, 100,100, $ white );Imagepng ($ image );Imagedestroy ($ image );?>
That is to say, we can use this function to output all vertices of a Chinese character.
In the chs16.fon file, it is saved in the national standard location code table (GB-2312 of basic character set of Chinese character encoding used for national standard information exchange ). It is a dot matrix font for Chinese characters. (In WIN98, this file is in c: windowscommand. If you want to use it in a UNIX system, pay at
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