MEMORY MEDIUM

TECHNICAL FIELD

The present invention generally relates to an input method, and more particularly, relates to a Chinese character input method, apparatus, and associated memory medium.

BACKGROUND ART

With widely application of portable electronic devices (for example, mobile phones, personal digital assistants PDA, etc.), a Chinese character input method has become one of the most importance applications in the portable electronic devices. The input speed, accuracy, and convenience of a Chinese character input method has also become an important index for consumers to select an electronic device.

At present, there are various kinds of Chinese character input methods. These Chinese character input methods may be categorized into two general classes, which are stroke input methods and phonetic symbol input methods. Stroke input methods comprise for example Cangjie input method, and Wbx input method. These stroke input methods typically require memorizing word roots, which are difficult to grasp. Phonetic symbol input methods comprise for example pinyin input method. However, for phonetic symbol input methods, users must know the pronunciation of a character, which thus can be barely used for users who are illiterate to or unfamiliar with pinyin.

Further, due to limited size of a portable electronic device, the keys it can provide are also limited. For example, the keys of most mobile phones do not exceed 20, while the keys dedicated for input mainly rely on 10 number keys, 4 navigation keys and 1 enter key, which results in more presses when inputting Chinese characters to a mobile phone, thereby lowering the input speed.

Therefore, it is desirable to provide a Chinese character input method which is easy to learn, has a quick input speed, and is particularly suitable for a portable electronic device such as a mobile phone.

SUMMARY OF THE INVENTION

An objective of the present invention is to provide a Chinese character input method, apparatus, and associated memory medium, which is particularly suitable for a portable electronic device, such that according to embodiments of the present invention, efficient Chinese character input is enabled with limited keys on a portable electronic device, with least bit error rate. According to an aspect of the present invention, there is provided a Chinese character input method, comprising: searching matched radicals based on an input basic stroke; displaying the searched radicals; responsive to selection of a radical, searching Chinese characters which match the selected radical based on a radical-Chinese character mapping table in which a radical is mapped to indexes of Chinese characters which belong to the radical in the Chinese character table; and displaying the searched Chinese characters.

According to another aspect of the present invention, there is provided an apparatus, comprising: a processor; a memory containing a computer program code; the memory and the computer program codes being configured to cooperate with the processor to enable the apparatus to at least implement: searching matched radicals based on an input basic stroke; displaying the searched radicals; responsive to selection of a radical, searching Chinese characters which match the selected radical based on a radical-Chinese character mapping table in which a radical is mapped to indexes of Chinese characters which belong to the radical in the Chinese character table; and displaying the searched Chinese characters.

According to a further aspect of the present invention, there is provided a Chinese character input apparatus, comprising: radical searching means configured to search matched radicals based on an input basic stroke; radical displaying means configured to display the searched radicals; Chinese character searching means, configured to, responsive to selection of a radical, search Chinese characters which match the selected radical based on a radical-Chinese character mapping table in which a radical is mapped to indexes of Chinese characters which belong to the radical in the Chinese character table; and Chinese character displaying means configured to display the searched Chinese character. According to a still further aspect of the present invention, there is provided a memory medium comprising a computer-readable program, wherein when the computer readable program is executed by a processor, the processor is enabled to implement the Chinese character input method according to an embodiment of the present invention. The Chinese character input method, apparatus and associated memory medium according to various embodiments of the present invention, due to utilize a two-level search from stroke to radical and then from radical to Chinese character, is capable of realizing a more efficient Chinese character input speed, Moreover, for Chinese characters with a radical and more strokes, their input speed can be efficiently improved over a conventional stroke input method.

Further, the Chinese character input method according to embodiments of the present invention conforms to customary habit in looking up a dictionary, thus users can grasp it without learning. According to the Chinese character input method based on the embodiments of the present invention, any Chinese character, regardless of whether its radical is in the initial position according to the writing sequence of the Chinese character, can be searched out based on the search from radical to Chinese character based on the embodiments of the present invention.

Besides, according to the embodiments of the present invention, selection frequency of a radical or word can be dynamically updated based on inputs of a user, such that a personal hot-word library is customized automatically for each user, thereby further improving the user's character input speed and user experience.

Additionally, according to the embodiments of the present invention, fuzzy search for strokes and/or radicals is enabled. Thus, a desired Chinese character may be quickly searched and input in case of not clearly knowing a specific stroke or radical. The above and other objectives, features and advantages may become apparent when reading the following detailed depiction on the illustrative embodiments with reference to the following accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will provide details of the preferred embodiments in the following description with reference to the drawings, wherein:

Fig. 1 shows a key arrangement diagram according to an embodiment of the present invention;

Fig. 2 shows a flow chart of a Chinese character input method according to an embodiment of the present invention; Figs. 3A and 3B show input examples according to an embodiment of the present invention;

Fig. 4 shows structural diagram of a Chinese character input apparatus according to an embodiment of the present invention; Fig.5 shows a portable device in which one illustrative embodiment of the present invention can be implemented; and

Fig.6 shows a configuration schematic of the portable device as shown Fig.5.

Like reference numerals designate the same, similar, or corresponding features or functions throughout the drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Now, the preferred embodiments of the present invention will be described in detail with reference to the drawings. In view of the fact that some users are illiterate to or unfamiliar with pinyin of a

Chinese character, an embodiment of the present invention provides a Chinese character input method based on a radical in accordance with a customary manner of looking up a dictionary.

In the following description, data information required by various embodiments of the present invention is described in a form of data table. However, the skilled in the art would appreciate that other forms of data structure may be used to describe such data information.

Similar to most conventional stroke input methods, basic strokes of Chinese characters may be summarized into 5 general classes: horizontal stroke— , vertical stroke I , left-falling stroke J , dot stroke ^N , and turning stroke ^~ " ^' , wherein the stroke "rising stroke" is deemed as horizontal stroke — , the stroke "vertical stroke with hook" is deemed as vertical stroke | ; the stroke "right-falling stroke" is deemed as dot stroke ^x ; and all strokes with hook are deemed as turning stroke ^"~ ' . The five general classes of strokes correspond to for example number keys 1, 2, 3, 4, 5 on a keyboard, respectively. The above information may for example be expressed as a basic stroke table shown in Table 1.

Table 1

Basic stroke Code Radical table Chinese Character index table index

— 1 ( 001 ) 1 1

1 2 ( 010) 43 990

J 3 ( 01 1 ) 91 2301 4 ( 100) 150 4030

-' 5 ( 101 ) 208 7098

As shown in Table 1, the first column represents the five basic strokes of Chinese characters, which are stored as Unicode codes. The second column represents stroke basic code of each basic stroke, which, for example, may be expressed by a three-bit binary system as (001, 010, 01 1, 100, 101) respectively. All Chinese characters and radicals may be coded based on their stroke basic codes. The third column represents the initial index positions of the radicals starting with respective basic stroke in a radical table (for example, Table 2 as described hereinafter), which is thus also called a radical table index. The fourth column represents the initial index positions of the characters starting with respective basic stroke in the Chinese character table (for example, Table 3 as described hereinafter), which is thus also called a Chinese character table index. Specific meanings of the third and fourth columns will be further described hereinafter.

Though Table 1 shows the five basic strokes of Chinese characters and their codes, the skilled in the art would appreciate that other stroke classification system of Chinese characters, for example, 8 strokes, may be used. Further, the correspondence relationship between basic strokes and keyboard is also schematic, and the skilled in the art may make various changes as required. Next, a radical table is created for radicals, as shown in the following Table 2.

Table 2

As shown in Table 2, the first column represents index code of radicals, which uniquely identify respective radical. The second column represents respective radicals, which are stored as Unicode codes. The third column represents radical codes encoding stroke sequences of radicals with stroke basic codes, which is also called radical basic code. The fourth column indicates the initial index positions of Chinese characters belonging to respective radical in the radical- Chinese character mapping table (Table 4 as described hereinafter), which is called mapping table index, the meaning of which will be further described hereinafter.

Assuming a radical has n strokes, since the number of each stroke needs 3 bits, the number of bits required by the radical basic code of each radical is (3*n) mod 8+1. The basic coding format is as follows:

-3*n- I—

Stroke code Padding

wherein, after strokes are encoded, if the number of bits is insufficient for an integral number of bytes, it is padded by all-zero code.

To enable a quick search, radicals are indexed in a certain sequence. For example, in the radical table as shown in Table, 2, radicals are indexed according to the sequence of basic strokes of the initial radical strokes. Specifically speaking, the radicals are ordered according to the initial radical strokes as horizontal stroke — , vertical stroke I , left-falling stroke ) , dot stroke , and turning stroke ^— ', respectively. In other words, the radical table may for example comprise 5 sub-tables. For example, the radicals with an index value from 1 to 42 are those radicals with an initial stroke as horizontal stroke "; the radicals with an index value from 43-90 are those radicals with an initial stroke as vertical stroke " I ", and so forth.

It can be seen from the above description that the radical table indexes in the third column of the basic stroke table as shown in Table 1 are directed to the initial index positions of radicals starting with respective basic strokes in the radical table (for example, Table 2). Through these simple indexes, after a user initially inputs a basic stroke, it may directly jump to the corresponding initial position in the radical table as shown in Table 2 according to the radical table index as shown in Table 1, thereby accelerating search. In various embodiments of the present invention, the index from a basic stroke to a radical is called a first level index. According to a preferred embodiment, in the radical table as shown in Fig. 2, for radicals with a same initial stroke, the radicals are indexed based on fixed frequencies of the radicals. In other words, in each of the above 5 sub-tables, radicals are ordered according the fixed frequencies of the radicals.

The fixed frequency of a radical is determined by the number n of Chinese characters belonging to the radical and the fixed frequency f, (i=l, n) of each Chinese . character. For example, the sum∑f, of fixed frequencies of all Chinese characters belonging to a same radical may be taken as the fixed frequency of the radical. Fixed frequency of a Chinese character refers to use frequency of the Chinese character, which may be obtained by for example analysis on various kinds of statistic data. In a preferred embodiment, radicals with the same fixed frequency of radical are ordered by the number n of the Chinese characters belonging to the radicals. For example, the radicals covering more Chinese characters are placed in front.

In a preferred embodiment, the radical table further comprises a dynamic frequency of each radical. Dynamic frequency of a radical refers to the times of selecting the radical by a user at the time of input. The dynamic frequency may be updated based on the user's input selection. In the case of searching out radicals through a radical table, the search results are ordered based on the fixed frequency and dynamic frequency of the radicals. Therefore, if the size of display area is limited, only the frequently used radical is displayed, which can efficiently improve the input speed and user experience.

For example, in a preferred embodiment, ordering is performed based on sums of a fixed frequency ratio and a dynamic frequency ratio of radicals, wherein fixed frequency ratio of a radical refers to the ratio of the fixed frequency of the radical to the total fixed frequency, while dynamic frequency ratio refers to the ratio of the times of inputting the radical by a user to the total times of inputting radicals by the user.

In a preferred embodiment, the radicals in Table 2 are not limited to include common radicals used in radical search of various kinds of dictionaries, but also include stroke modules located in the front part of a stroke sequence of a Chinese character. For example, for the Chinese character "¾fc", it is conventionally searched through the radical "^ " when it is looked up in a dictionary. However, in writing, is written before "i ". Thus, the radicals in Table 3 may further comprise " so as to look up a Chinese character based on the writing habit of people. Except otherwise pointed out explicitly, "radicals" in this context comprises radicals in the above two senses.

With reference to Table 2, to encode radicals with index code and radical basic code can simplify search manner of Chinese characters and realize fuzzy search of radicals in Chinese characters, and meanwhile it avoids the phenomenon of coincident codes caused by coding only with radical basic code.

Next, a Chinese character library is established for all Chinese characters. In this library, each character is stored in the manner of Unicode codes. Then, different indexes are compiled on the basis of this standard character library. Table 3 shows an exemplary Chinese character library, which is also called a Chinese character table.

Table 3

As shown in Table 3, the first column represents indexes of Chinese characters, which uniquely identify respective Chinese characters. The second column represents respective Chinese characters, which are stored as Unicode codes.

In a preferred embodiment, in order to be compatible with the conventional stroke input methods, there is a third column in the Chinese character table, which represents a Chinese character code for coding the stroke sequence of the Chinese character with the stroke basic code, which is called Chinese character basic code.

Similar to a radical basic code, the coding format of a Chinese character basic code is as follows,

Stroke code Padding

wherein n indicates the number of strokes of a Chinese character.

In another embodiment, the Chinese character table comprises a fourth column, which represents a stroke code for coding the part other than the radical of a Chinese character, and is called a Chinese character radical code. For example, the basic coding format of a Chinese character radical code is as follows:

Remaining stroke

Padding

code In this basic coding format, the flag is 1 bit, which indicates whether the stroke of the Chinese character starts with a radical. If so, then the flag is 0, otherwise it is 1. The remaining stroke codes indicate the codes of the remaining strokes of the Chinese character except for the radical, wherein m represents the number of strokes of the Chinese character except for the radical.

For example, the basic code of the Chinese character "ϊ¾" is:

4512213251 Padding

wherein "45" is the basic code of the radical "i ". Based on the above rule, the Chinese character radical code of "i¾r" is:

if 12213251 Padding

, which is shorter than the basic code.

For any Chinese character, there may be a corresponding Chinese character radical code. If the structure of a Chinese character is hard to be split and then it is hard to determine the radical, the first basic stroke of this Chinese character may be taken as its radical. For a Chinese character which may have a plurality of radicals, for example its radical may be or " ij", and then it also has a plurality of corresponding Chinese character radical codes. In a preferred embodiment, a Chinese character basic code is used to code the Chinese character, which is compatible to the conventional stroke input methods and supports direct search of the Chinese character based on the input stroke. In another preferred embodiment, a Chinese character radical code is used to code the Chinese character, which enables fuzzy search of the radical in the Chinese character, as described hereinafter.

Similar to the radical table, in the Chinese character table as shown in Table 3, Chinese characters are indexed based on the sequence of initial basic strokes. Specifically, the Chinese character table may comprise 5 sub-tables based on the initial strokes of Chinese characters, which are horizontal stroke — , vertical stroke I , left-falling stroke J , dot stroke ^ , and turning stroke ^~~ respectively. For example, as shown in Table 3, the Chinese characters with an index value from 1 to 989 are all Chinese characters with the initial stroke as horizontal stroke ". The Chinese characters with an index value from 990 to 2300 are all Chinese characters with the initial stroke as vertical stroking " I ". The Chinese characters with an index value from 2301 to 4029 are all Chinese characters with the initial stroke as left-falling stroking " J ", and so forth.

It can be seen from the above description of Table 1 that the Chinese character indexes in the fourth column of the basic stroke table as shown in Table 1 are directed to the initial index positions of Chinese characters starting with respective basic strokes in the Chinese character table (for example, Table 3). Through these simple indexes, after a user initially inputs a basic stroke, it may directly jump to the corresponding initial position in the Chinese character table as shown in Table 3 according to the Chinese character table index as shown in Table 1, thereby accelerating search.

According to a preferred embodiment, in the Chinese character table as shown in Table 3, for Chinese characters with a same initial stroke, Chinese characters are indexed by fixed frequencies of the Chinese characters. In other words, in each of the above 5 sub-tables, Chinese characters are ordered according to the fixed frequencies of the Chinese characters. As previously mentioned, fixed frequencies of Chinese characters may be obtained through analysis on various kinds of statistic data.

In a preferred embodiment, the Chinese character table further comprises dynamic frequencies of Chinese characters. Dynamic frequency of a Chinese character refers to the times of selecting the Chinese character by a user at the time of input. The dynamic frequency may be updated based on the user's input selection. In the case of searching Chinese characters through the Chinese character table, the search results are ordered based on the fixed frequencies and dynamic frequencies of the Chinese characters. Therefore, if the size of display area is limited, only the frequently used Chinese characters are displayed, which can efficiently improve the input speed and user experience.

Similar to radicals, for example, ordering may be performed based on the sum of fixed frequency ratios and dynamic frequency ratios of Chinese characters, wherein fixed frequency ratio of a Chinese character refers to the ratio of the fixed frequency of the Chinese character to the total fixed frequency, while dynamic frequency ratio refers to the ratio of the times of inputting the Chinese by a user to the total times of inputting Chinese characters by the user.

Further, mapping is constructed between the radical table and the Chinese character table, which is called a radical- Chinese character mapping table. In this table, the indexes of all Chinese characters corresponding to respective radicals in the Chinese character table are stored in sequence. Table 4 shows an example of a radical- Chinese character mapping table.

Table 4

Mapping index Chinese character index in Chinese character table

1 1

2 2

3 3

153 230 154 233

187 412

. . .

As shown in Table 4, the first column represents mapping indexes, which uniquely identify each Chinese character corresponding to each radical. The second column represents the indexes of Chinese characters belonging to the radicals in the Chinese character table. For example, as shown in Table 4, the mapping indexes 1 to 152 correspond to indexes of all Chinese characters with "— " as the radical; mapping indexes 153 to 186 correspond to indexes of all Chinese characters with " l" as the radical; and so forth.

It can be seen from the above description that the fourth column in the radical table as shown in Table 2 represents the initial index positions of the Chinese characters belonging to the radicals in the radical-Chinese character mapping table (for example, Table 4). With these simple indexes, after a user selects a radical, it may directly jump to the corresponding initial position in the radical- Chinese character mapping table in Table 4 based on the mapping table indexes in the radical table (for example, Table 2), thereby accelerating search. In various embodiments of the present invention, the index from a radical to Chinese characters is called a second level index.

In the radical- Chinese character mapping table, since mapping is constructed between radicals and Chinese characters, it enables radicals to exactly correspond to Chinese characters, and vice versa. Compared with searching Chinese characters only by means of a radical's stroke sequence, error bit occurrence is avoided.

Besides, by constructing mapping between radicals and Chinese characters, regardless of whether a Chinese character radical is in the initial stroke position of its stroke sequence, the Chinese characters belonging to the radical can be found through the radical. Such two-level index manner of searching a radical first and then mapping to Chinese characters from the radical provides an input method identical to a dictionary lookup. This input method, for example, may also be applied to various kinds of learning machines so as to enlighten children. Fig. 1 shows a key arrangement diagram according to an embodiment of the present invention. As shown in Fig. 1, the five numbers keys 1, 2, 3, 4, and 5 on a keypad are distributed with five basic strokes respectively, i.e., horizontal stroke— ^■ , vertical stroke I , left-falling stroke J , dot stroke ^N , and turning stroke The keypad in Fig. 1 may be a virtual keypad or a physical keypad. The keypad may be provided on various kinds of electronic devices which require using a keypad, such as a mobile phone, a personal digital assistant PDA, and a personal computer.

The skilled in the art would appreciate that though Fig. 1 shows a key arrangement diagram, these five basic strokes may be allocated in other manner.

Hereinafter, a Chinese character input method according to various embodiments of the present invention is described with reference to the previously created data table and the flow as shown in Fig. 2. The flow starts from step S200, wherein a basic stroke input by a user is received.

Then, at step S201 , matched radicals are searched based on the basic stroke input by the user. Specifically speaking, after the user inputs a first basic stroke, radical table indexes corresponding to the input basic stroke are looked up in the basic stroke table as shown in Table 1 , thereby obtaining an index range. For example, the values between radical table index values of two neighboring basic strokes in the basic stroke table (Table 1) are the mappings of all radicals corresponding to a preceding basic stroke. Then, based on the radical table indexes, it quickly jumps to the initial index positions of the radicals starting with the basic stroke in the radical table (for example Table 2).

Next, at step S202, the searched radicals are displayed. Due to limited display area in an electronic device, only a limited number (for example 6) of radicals are displayed. In a preferred embodiment, radicals, for example 6 radicals, may be retrieved in sequence for display from the initial index positions. In another preferred embodiment, the searched radicals are ordered based on the fixed frequency and dynamic frequency of the radicals, and for example the first 6 results are displayed.

In an alternative embodiment, upon searching and displaying radicals, Chinese characters which match an input basic stroke are further searched based on the Chinese character basic code in the Chinese character table (for example Table 3), and the searched Chinese characters are displayed.

For example, after the user inputs a first basic stroke, Chinese character table indexes corresponding to the input basic stroke are looked up in the basic stroke table as shown in Table 1, thereby obtaining an index range. Similarly, the values between Chinese character table index values of two neighboring basic strokes in the basic stroke table (Table 1) are the mappings of all Chinese characters corresponding to a preceding basic stroke. Then, based on the Chinese character table indexes, it quickly jumps to the initial index positions of the Chinese characters starting with the basic stroke in the Chinese character table (for example Table 3). Similar to displaying radicals, upon displaying Chinese characters, the searched Chinese characters may be ordered and displayed based on fixed frequencies and dynamic frequencies of Chinese characters.

If the displayed radicals or Chinese characters include the desired radical or Chinese character, it will be selected and put on the top screen. Otherwise, reception of stroke inputs continues. With continuing input of strokes, the displayed radicals or Chinese characters are refurbished. In a preferred embodiment, matched radicals are searched in the radical table with the radical basic codes based on the input stroke; and additionally, matched Chinese characters are searched in the Chinese character table according to the Chinese character basic code based on the input stroke. The above process is repetitively performed till the desired radical or Chinese character appears.

Next, at step S203, responsive to selection of a radical, Chinese characters matching the selected radical are searched based on the radical- Chinese character table. Specifically, after selecting a radical, mapping table indexes of the selected radical are found in the radical table (for example Table 2), thereby obtaining an index range. For example, the values between mapping table index values of two neighboring radicals in the radical table (Table 2) are the mappings of all Chinese characters corresponding to a preceding radical. Next, based on the mapping table indexes, it quickly jumps to the initial index positions of the Chinese characters belonging to the radical in the radical- Chinese character mapping table (for example Table 4).

In the radical- Chinese character mapping table, all Chinese characters belonging to the radical are mapped to the radical. Thus, through the radical— Chinese character mapping table, indexes of corresponding Chinese characters in the Chinese character table (for example Table 3) may be quickly searched. With these indexes, corresponding Chinese characters may be retrieved from the Chinese character table.

Next, at step S204, the searched Chinese characters are displayed. Likewise, due to limited display area in an electronic device, only a limited number (for example 6) of Chinese characters are displayed. In a preferred embodiment, Chinese characters, for example 6, may be taken in sequence for display from the initial index position. In another preferred embodiment, the searched Chinese characters are ordered based on the fixed frequency and dynamic frequency of the Chinese characters and for example the first 6 results are displayed. If the displayed Chinese characters include the desired Chinese character, it will be selected and put on the top screen. Otherwise, reception of stroke inputs continues. At this time, the user inputs remaining strokes except for the radical.

With continuing input of strokes, matched Chinese characters are searched in the Chinese character table, and displayed Chinese characters are refurbished.

In a preferred embodiment, matched Chinese characters are searched based on the Chinese character basic code in the Chinese character table. Since the radical- Chinese character mapping table has limited the index range of the Chinese characters belonging to the radical, matched Chinese characters may be searched within this index range.

In another preferred embodiment, if the Chinese character table includes Chinese character radical codes, matched Chinese characters may be searched based on the Chinese character radical codes in the Chinese character table. Likewise, matched Chinese characters may be searched within the index range as defined in the radical- Chinese character mapping table. Since the Chinese character radical code only codes the strokes other than the radical, quick match is enabled based on the subsequently input remaining strokes.

The above process is repetitively performed till the desired Chinese character appears.

In a still further embodiment, responsive to selection of a radical, the dynamic frequency of the radical is updated; thereby the sequence of displaying the radical may be dynamically updated; and/ or responsive to selection of a Chinese character, the dynamic frequency of the Chinese character is updated; thereby the sequence of displaying the Chinese character may be dynamically displayed.

In a preferred embodiment, fuzzy query of strokes and/or radicals may be supported. For example, if the Chinese character table uses Chinese character radical codes to code, radicals may be replaced with the symbol "*", so as to support fuzzy query of radicals. The remaining strokes other than the radical may be replaced with the symbol "? " , so as to support fuzzy query of remaining strokes. If the Chinese character table uses Chinese character basic codes to code, fuzzy query of arbitrary stroke of Chinese characters is enabled.

For example, the Chinese character may be obtained by the following inputs: i¾ = * 12213251 ;

=??12213251; =45??213251;

=*??21 ??51 ; ..

In addition, when a radical of a Chinese character is not in the initial position of the Chinese character, the user may use a "*" symbol to match. For example, "f'J" may be queried through the following inputs:

=1 12*;

=???*; . · ·

Further illustration of the input method of various embodiments of the present invention is made hereinafter with reference to Figs. 3A and 3B with the Chinese character as an example.

Firstly, the user inputs a stroke ". A radical table index and a Chinese character table index corresponding to the stroke " ^~ are searched from the basic stroke table (for example Table 1), and in this example, their values are both 1. And then it jumps to the radical table (for example Table 2) to search radicals starting with ". The searched radicals are ordered and then displayed. Similarly, Chinese characters starting with "— " are searched from the Chinese character table (for example Table 3), which are then ordered and displayed. For example, in Fig. 3 A which show displaying information, the middle line of Fig. 3A shows user input, the top line shows searched characters, and the bottom line shows searched radicals. The user selects a radical " fc" from the displayed radicals. Responsive to selection of the radical "7 ", the index range of the radical-Chinese character mapping table (for example Table 4) to which the radical "/ " corresponds is found from the radical table (for example Table 2). Next, through the radical- Chinese character mapping table, indexes of all Chinese characters with "^" as the radical in the Chinese character table are retrieved. Corresponding Chinese characters are retrieved from the Chinese character table based on these indexes and then ordered and displayed according to a certain rule. For example, in Fig. 3B which shows displaying information, the top line shows the searched characters, and the bottom line shows user input. Finally, the user selects to finalize the input from the displayed Chinese characters.

The Chinese character input method according to various embodiments of the present invention, due to utilization of a two-level search from stroke to radical and then from radical to Chinese character, is capable of realizing a more efficient Chinese character input speed.

For example, based on fixed frequencies of words, Monte Carlo algorithm is used to simulate user input of 1 million words. Statistics is made on the minimum number of key presses to work out the average number of key presses. The minimum number of key presses indicates the minimum times of input required for the desired Chinese character appearing on the first page of the screen. The simulation result shows that for all Chinese characters, the average number of key presses with the conventional stroke input methods is 5.98249, while the average number of key presses according to the embodiments of the present invention is 4.73161, The simulation result also shows that for all Chinese characters with explicit radical, the average number of key presses with the conventional stroke input methods is 6.19939, while the average number of key presses according to the embodiments of the present invention is 4.30766. Accordingly, the input method of the embodiments is particularly suitable for Chinese characters with radicals and more strokes.

Further, the Chinese character input method according to embodiments of the present invention conforms to customary habit in looking up a dictionary, thus users can grasp it without learning. With the Chinese character input method according to the embodiments of the present invention, any Chinese character, regardless of whether its radical is in the initial position of the writing sequence of the Chinese character, can be searched based on the radical- Chinese character mapping table according to the embodiments of the present invention.

Besides, with the embodiments of the present invention, radical and word selection frequency can be dynamically updated based on inputs of a user, such that a personal hot-word library is customized automatically for each user, thereby further improving the user's character input speed and user experience.

Additionally, with the embodiments of the present invention, fuzzy search for strokes and/or radicals is enabled. Thus, a desired Chinese character may also be quickly searched and input in case of not clearly knowing a specific stroke or radical.

Fig. 4 shows a structural diagram of an input apparatus according to a preferred embodiment of the present invention, wherein the reference sign 400 indicates an input apparatus; reference sign 401 indicates radical search means; reference sign 402 indicates radical display means; reference sign 403 indicates Chinese character search means; and reference sign 404 indicates Chinese character display means.

In a preferred embodiment, the radical search means 401 is configured to search matched radicals based on an input basic stroke. The radical display means 402 is configured to display the searched radicals. Further, responsive to selection of a radical, the Chinese character search means 403 is configured to search Chinese characters matching the selected radical based on the radical -Chinese character mapping table. The Chinese character display device 404 is configured to further display the searched Chinese characters.

Fig. 5 and Fig. 6 show an illustrative mobile device 12 in which the present invention may be implemented. However, it should be understood that the present invention does not intend to be limited in a particular type of electronic device. The mobile device 12 as shown in Figs. 5 and 6 comprises a housing 30, a display 32 in a form of LCD display, a keypad 34, a microphone 36, an earphone 38, a battery 40, an infrared port 42, an antenna 44, and a smart card 46 in a form of UICC according to an embodiment of the present invention, a card reader 48, a radio interface circuit 52, a codec circuit 54, a controller 56, and a memory 58. An individual circuit and element may be any type known in the art, for example a mobile phone within the scope of Nokia.

The present invention further provides a memory medium comprising a computer-readable program, which, when the computer-readable program is executed by a processor, enables the processor to realize the input method of a virtual keypad according to the embodiments of the present invention. The memory medium may be any tangible medium, for example, a floppy disk, CD-ROM, DVD, a hard-disk driver, and even a network medium, etc.

The various aspects of what is described above can be used alone or in various combinations. The teaching of this application may be implemented by a combination of hardware and software, but can also be implemented in hardware or software. The teaching of this application can also be embodied as computer program product on a computer readable medium, which can be any material media, such as floppy disks, CD-ROMs, DVDs, hard drivers, even network media and etc.

The specification of the present invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the invention in the form disclosed, Many modifications and variations will be apparent to those of ordinary skill in the art. It is understood by those skilled in the art that the method and means in the embodiments of the present invention can be implemented in software, hardware, firmware or a combination thereof.

Therefore, the embodiments were chosen and described in order to better explain the principles of the invention, the practical application, and to enable others of ordinary skill in the art to understand that all modifications and alterations made without departing from the spirit of the present invention fall into the protection scope of the present invention as defined in the appended claims.