CN1794343A - Method of generating line field signal beneficial to realize digital video frequency image contraction and enlargement interpolation - Google Patents

Abstract

This invention discloses a method for generating line-field signals suitable for realizing convergent-divergent interpolating of a digital video image, which inputs and regulates to output line-field signals synchronously in a double three interpolating device on a one dimension direction and the accumulated circulation length is limited in 63 lines so as to reduce the accumulation error and meet the periodic requirement for outputting line-field signals.

Description

A kind of row field signal production method of realizing the zooming digital video image interpolation that is beneficial to

Technical field

The invention belongs to digital video image and handle and the display technique field, be specifically related to a kind of row field signal production method of realizing the zooming digital video image interpolation that is beneficial to.

Background technology

Zooming digital video image chip (Scaler) is the indispensable part of flat-panel display device, realize the function of image resolution ratio conversion, and the image zoom interpolation algorithm is the core algorithm of zooming digital video image chip.

The image zoom interpolation algorithm is commonly used arest neighbors interpolation, bilinear interpolation and bicubic interpolation, and wherein the effect of bicubic interpolation is best, but calculated amount and hardware implementation complexity are more much bigger than preceding two kinds of algorithms.

And Fig. 1 is the device of bicubic interpolation on a kind of realization one dimension direction of saving hardware resource, supports and one of the key that realizes this device is exactly a production method of exporting row field signal.

On above-mentioned realization one dimension direction in the device of bicubic interpolation, by line of input field signal control data write store (line storage such as registers group or some storer such as fifo), control around the current interpolation point 4 point data in 4 neighborhoods by the output row field signal and read from storer and send into the interpolation calculation module, the back output data is finished the bicubic interpolation process as calculated.The advantage of this device is to need not the fifo buffer memory before and after the data-carrier store, save hardware resource, and the read-write steering logic is simple.But this just requires writing of data-carrier store and reads the synchronism that will keep certain, promptly can not have to write the situation generation of catching up with and surpassing or lagging behind and reading.Simultaneously, this device also can be realized bilinear interpolation and arest neighbors interpolation.

For realizing this device, be to the requirement of exporting row field signal:

1, guarantees the periodicity of output row field signal.Though flat-panel display device is so strict unlike CRT to the periodic requirement of vision signal row field, the panel that different vendor produces has different requirements to the line of input field, and the periodicity row field signal of outputting standard will have versatility undoubtedly.

2, guarantee the synchronism of input, output row field signal, promptly satisfy the synchronism of the read-write operation of data-carrier store, can not take place that read-write is super catches up with, guarantee that 4 required field pixel values of current interpolation point computing are present in the data-carrier store and can read under the control of output row field signal.

Summary of the invention

Have problems at row field signal in the image interpolation implement device that proposes in the background technology, the objective of the invention is to, propose a kind of row field signal production method of realizing the zooming digital video image interpolation that is beneficial to.This method can satisfy these 2 requirements of synchronism that periodicity (2) that (1) guarantee the output row field signal guarantees input, output row field signal, helps realizing the image interpolation implement device of the saving hardware resource mentioned in the background technology.

To achieve these goals, technical scheme of the present invention, a kind of row field signal production method of realizing the zooming digital video image interpolation that is beneficial to, it is characterized in that, adopt line of input field signal modulation output row field signal in the device of this method bicubic interpolation on the one dimension direction, guarantee both synchronisms, and a length of the cycle of accumulated counts is limited in 63 row, dwindle add up error, satisfy the periodicity requirement of output row field signal.Details are as follows for this method:

The synchronism of 1, input, output row field signal and periodicity

Data need be because the variation of clock zone can take place before and after the convergent-divergent through storer in the image interpolation implement device that proposes in the background technology, promptly change frequently; But because of not using the outer SDRAM of sheet, so can't realize the field frequency of vision signal changes, the cycle that just import, output field reaches useful signal synchronously is constant, and writing data into memory could begin to read desired data and carries out interpolation calculation after need waiting for times of 3 row, therefore will differ the time delays of input 3 row between input, the output field useful signal.And the line number in every before and after the convergent-divergent, the ratio of promptly importing, export the number of capable synchronous head equals the scaling factor, that is to say if the scaling factor is m/n, so every m that imports is in the capable time, n is capable in output, line of input reach synchronously the capable time of useful signal m with output row synchronously and the capable time of useful signal n equate.

The synchronism of input, output row field signal is exactly to satisfy the time delays that constant and useful signal of cycle of the field synchronization of above-mentioned (1) input, output and useful signal differs input 3 row, (2) line of input reach synchronously the capable time of useful signal m with the output row synchronously and the capable time of useful signal n equate these two conditions.

The periodicity of input, output row field signal is exactly that the pixel of every row of row field synchronization and useful signal is counted and is consistent, but flat-panel display device can be tolerated error to a certain degree.

2, row synchronously and the production method principle of useful signal

If the scaling factor is m/n, realize for the ease of hardware, require this scale factor to be the simplest prime number ratio, and m, n＜64 (also can be 32) if reduce accuracy requirement; Other establishes the every capable transmission time of input, output, synchronous signal cycle is respectively hperiod_in and hperiod_out at once, imports the total pixel of every row and counts and be htotal_in, input clock cycle Tclk, then according to the condition (2) of above-mentioned synchronism, their pass is:

$\mathrm{hperiod}\_\mathrm{out}=\mathrm{hperiod}\_\mathrm{in}*\frac{m}{n}=\mathrm{Tclk}*\mathrm{htotal}\_\mathrm{in}*\frac{m}{n}$

Drawn by following formula, input is every $(\mathrm{hnum}\_\mathrm{trans}=\mathrm{htotal}\_\mathrm{in}*\frac{m}{n})$ The time of individual picture element is exactly the transmission time of output delegation, therefore as long as in the input clock territory, the input picture element is counted (promptly to the input clock counting), every hnum_trans picture element produces a reset signal, then to the zero clearing under this signal effect of output clock count, can produce the synchronous and useful signal of output row by high level (or low level) starting and ending position is set, and satisfy the synchronism requirement.

Simultaneously, a length of the cycle of aforesaid operations equals m, be every input m capable be that zero clearing restarts new round count cycle, like this accumulated counts error limitation in each round-robin last column, the pixel of just exporting the capable last column of every n more or less some error of counting, but this error is an acceptable for flat-panel display device, can normally show, has therefore satisfied periodically requirement.

3, field synchronization and useful signal production method principle

By the negative edge pulse of input field synchronization head as reset signal, the output line synchronizing signal that has produced is gone counting, by high level (or low level) starting and ending position is set, and consider that the output field useful signal will lag behind the 3 capable times of importing of an input useful signal, can produce output field and reach useful signal synchronously, and satisfy synchronism.

Because the output row reaches the periodicity requirement that useful signal has satisfied flat-panel display device synchronously, field synchronization of Chan Shenging and useful signal by the modulation of input field sync signal, are enough to satisfy the periodicity requirement simultaneously on this basis.

The image interpolation implement device that row field signal production method of the present invention helps realizing in the background technology to be mentioned makes these device data-carrier store front and back need not the fifo buffer memory, save hardware resource, and the read-write steering logic is simple.Method of the present invention is exported row field signal with the modulation of line of input field signal, satisfied the synchronism of the desired output row field signal of this device, made 4 required field pixel values of current interpolation point computing be present in the data-carrier store and can under the control of output row field signal, read; Accumulated counts length of the cycle is limited in 63 row in addition, dwindles add up error, thereby the periodicity of output row field signal satisfies the requirement of this device, makes that the vision signal behind the convergent-divergent can normally show on flat-panel display device.

Description of drawings

Fig. 1 is the structure drawing of device of bicubic interpolation on the one dimension direction;

Fig. 2 is a row field signal production method synoptic diagram of the present invention;

Fig. 3 is that row reaches useful signal production method synoptic diagram synchronously;

Fig. 4 is field synchronization and useful signal production method synoptic diagram;

Fig. 5 is an output row count status machine state transition graph;

Below in conjunction with accompanying drawing the present invention is further described in detail.

Embodiment

Referring to Fig. 2, row field signal production method of the present invention is modulated by the line of input field signal and is produced the output row field signal, needs the scaling factor and other parameters such as hnum_trans etc. to participate in calculating simultaneously.Describe in detail below in conjunction with Fig. 3 and Fig. 4.

Referring to Fig. 3, the present invention's row reaches the useful signal production method synchronously and comprises: trigger pip generation module 1, line of input counting number module 2, input clock counting module 3, output clock count module 4, and details are as follows:

1, trigger pip generation module

First input field synchronization negative edge after trigger pip trigger is resetted by systematic reset signal (effectively low) begins effectively, and after this all operations is all carrying out, and guarantees the modulating action of input field sync signal to the output row field signal, to satisfy synchronism.

2, line of input counting number module

By the line of input synchronous head is counted, the negative edge of per three capable synchronous heads produces a pulse, generates cycle count reset signal loop_clr, and the capable pressure of every input m zero clearing begins the operation of new round count cycle.Like this, the accumulated counts error just is limited in the capable last column of the every n of output, makes the periodicity of exporting row field signal satisfy the requirement of flat-panel display device.

3, input clock counting module

By in the input clock territory picture element being counted, every counting hnum_trans promptly produces a pulse, generates the output row and counts reset signal ohs_clr synchronously.It should be noted that counting forces zero clearing when running into the loop_clr pulse.

4, output clock count module

By in the output clock zone, picture element being counted, zero clearing under the pulse action of ohs_clr reaches the useful signal low level synchronously according to row and begins and finish parameter value ohs_st, ohs_end, ohref_st, the ohref_end value generates line synchronizing signal ohs and row useful signal ohref.

Referring to Fig. 3, field synchronization of the present invention and useful signal production method comprise: output row count status machine module 5, output line number counting module 6, and details are as follows:

5, output row count status machine module

Referring to Fig. 4, this state machine is a circulation every of state exchange, and its state transition process is state0 → state1 → state2 → state0 in one, before a next field synchronization negative edge, remain on no longer saltus step of state0, avoided unnecessary upset, save power consumption.

If current state (current state) is when being state2, the negative edge of the synchronous head of being expert at produces a pulse, produces output field and counts reset signal ovs_clr synchronously.

It should be noted that all operations all carries out when the trigger signal is effective.

6, output line number counting module

In the output clock zone, to exporting capable synchronous head counting, zero clearing under the pulse action of ovs_clr, begin and finish parameter value ovs_st according to field synchronization and useful signal low level, ovs_end, ovblk_st, the ovblk_end value generates line synchronizing signal ovs and row useful signal ovblk, especially, the value of ovblk_st and ovblk_end will guarantee that the effective ovblk signal of output field satisfies and an input useful signal differs the requirement that input 3 line times postpone.

Claims (3)

1. one kind is beneficial to the row field signal production method of realizing the zooming digital video image interpolation, it is characterized in that, with line of input field signal modulation output row field signal, guarantee both synchronisms, and a length of the cycle of accumulated counts is limited in 63 row, dwindle add up error, satisfy the periodicity requirement of output row field signal.

2. the method for claim 1, it is characterized in that described row reaches the useful signal production method synchronously and comprises a trigger pip generation module (1), a line of input counting number module (2), an input clock counting module (3), an output clock count module (4);

In the trigger pip generation module, first input field synchronization negative edge after the trigger of trigger pip is resetted by systematic reset signal begins effectively, after this all operations is all carrying out, and guarantees the modulating action of input field sync signal to the output row field signal, to satisfy synchronism;

Line of input counting number module is by counting the line of input synchronous head, and the negative edge of per three capable synchronous heads produces a pulse, generates cycle count reset signal loop_clr, and the capable pressure of every input m zero clearing begins the operation of new round count cycle.Like this, the accumulated counts error just is limited in the capable last column of the every n of output, makes the periodicity of exporting row field signal satisfy the requirement of flat-panel display device;

The input clock counting module is by counting picture element in the input clock territory, and every counting hnum_trans promptly produces a pulse, generates the output row and counts reset signal ohs_clr synchronously.It should be noted that counting forces zero clearing when running into the loop_clr pulse;

Output clock count module is by counting picture element in the output clock zone, zero clearing under the pulse action of ohs_clr, reach the useful signal low level synchronously according to row and begin and finish parameter value ohs_st, ohs_end, ohref_st, the ohref_end value generates line synchronizing signal ohs and row useful signal ohref.

3. the method for claim 1 is characterized in that, described field synchronization and useful signal production method comprise: output row count status machine module (5), output line number counting module (6);

Output row count status machine module is a circulation every of state exchange, its state transition process is state0 → state1 → state2 → state0 in one, before a next field synchronization negative edge, remains on no longer saltus step of state0, avoid unnecessary upset, saved power consumption;

If current state (current state) is when being state2, the negative edge of the synchronous head of being expert at produces a pulse, produces output field and counts reset signal ovs_clr synchronously;

All operations all carries out when the trigger signal is effective;

Output line number counting module is in the output clock zone, to exporting capable synchronous head counting, zero clearing under the pulse action of ovs_clr, begin and finish parameter value ovs_st according to field synchronization and useful signal low level, ovs_end, ovblk_st, the ovblk_end value generates line synchronizing signal ovs and row useful signal ovblk, especially, the value of ovblk_st and ovblk_end will guarantee that the effective ovblk signal of output field satisfies and an input useful signal differs the requirement that input 3 line times postpone.