JPH0315986A - Surface temperature display device - Google Patents

Abstract

PURPOSE:To obtain a correct temperature distribution diagram by detecting a picture element positioned on a temperature boundary where two picture elements of different temperature adjoin each other, and generating an isothermal line by considering this picture element as a denotative status. CONSTITUTION:A receiving and demodulating part 1 receives an electromagnetic wave including earth surface (including sea surface) temperature information measured by a satellite, and demodulates it into an analog voltage signal corresponding to the temperature, and an A/D converter 2 converts the analog signal into a digital signal corresponding to its level, and a buffer memory 3 stores the digitized picture element data of a necessary area portion. Then, the picture element positioned on the temperature boundary where two picture elements of the different temperature adjoin each other is detected in an overall control arithmetic circuit 8, and for instance, a noise which is probably included in a picture information signal and probably appears on a surface temperature distribution diagram is removed, and the isothermal line is generated. Thus, the correct temperature distribution diagram can be displayed.

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to a device for displaying a water surface temperature distribution map used in fishing, etc., and in particular to image processing for creating a temperature distribution map based on surface temperature information transmitted from a satellite. Regarding equipment.

BACKGROUND OF THE INVENTION This type of image processing apparatus receives and demodulates a ground surface temperature distribution image broadcast from a satellite using VHF radio waves, and converts it into an analog voltage signal indicating the temperature level.

An analog voltage signal is converted into a digital signal by an A/D converter, and each pixel data is stored in a memory.

The stored data is read out from the memory as pixel data in synchronization with the display cycle on a CRT (cathode ray tube).

According to the pixel data value, a look-up table memory in which display color data is written in advance is referred to, and the corresponding pixel is colored and displayed on the CRT display screen according to the value.

The contents of the lookup table can be changed arbitrarily, and by the above processing, points (pixels) at an arbitrary temperature level can be displayed in an arbitrary color.

Using separately obtained satellite orbit data, the latitude and longitude of the image received from the satellite is calculated, and the latitude and longitude lines are displayed in an overlapping manner.

By specifying the address of a pixel, the latitude/longitude and temperature of that pixel can be calculated.

By specifying latitude and longitude, the address of the corresponding pixel can be calculated and the temperature at that point can be determined.

Problems to be Solved by the Invention In the conventional apparatus described above, the temperature boundary line blurs or changes due to noise due to the influence of noise in the wireless transmission system, making it impossible to obtain a clear received image. Therefore, it is difficult to grasp accurate temperature distribution. It is difficult to understand how the temperature changes. There were various drawbacks, such as the fact that temperature changes in small areas could not be determined without referring to information from the pond information provider, and it was therefore difficult to make accurate judgments in real time based on real-time information.

Also, as the received image is greatly enlarged, the display of each pixel becomes like a mosaic pattern, which a) becomes difficult to see when enlarged, and b) makes it difficult to estimate changes in small parts.
c) It became difficult to understand which part of the whole the enlarged display area corresponded to, and there were problems such as having to remember the positional relationship.

A first object of the present invention is to provide an image processing device that can display an accurate temperature distribution map without noise being displayed on the screen.

Means for Solving the Problems In order to achieve this object, the present invention receives surface temperature information measured by a satellite and transmitted from the satellite, and creates a surface temperature distribution map in a rectangular shape according to the surface temperature information. An image processing apparatus that draws images pixel by pixel is characterized in that it includes a noise removing means for removing noise that is contained in an image information signal and that would appear in a surface temperature distribution map.

Furthermore, the second invention of the present invention is that even if the temperature distribution map is enlarged and displayed, the temperature distribution is displayed as a smooth line without a mosaic pattern on the boundary line of the temperature distribution, and the temperature distribution is easy to read. An object of the present invention is to provide an image processing device that displays a distribution map.

In order to achieve this object, the second invention is equipped with a smoothing means that performs image processing to make a step-like boundary line appearing on a boundary between different temperatures on a temperature distribution map into a smooth line. Features.

Embodiment In FIG. 1, a receiving demodulator 1 receives radio waves broadcast from a satellite and includes information on the temperature of the earth's surface (including the ocean) measured by the satellite, and demodulates it into an analog voltage signal corresponding to the temperature. The A/D converter 2 converts the analog signal into a digital signal according to its level. The buffer memory 3 stores digitally converted pixel data in a required area.

The display control circuit 4 controls writing and reading of the display memory 5 and controls the display timing of the CRT 7 and the like.

The lookup table 6 is generated by the comprehensive control calculation circuit 8.
RGB display level data corresponding to each pixel level data is written, and according to the pixel level data read out from the display memory 5, the display color data of the pixel is output to the CRT display device. The CRT display device 7 displays each pixel in the color according to the display color data. A general control arithmetic circuit (hereinafter referred to as CPU) 8 controls reading and writing of the buffer memory, controls instructions such as display conditions to the display control circuit, controls writing display color data to the lookup table, and writes data from the buffer memory to the display memory. Gives data transfer instructions, etc. Further, pixel data is read out from the buffer memory 3, and after arithmetic processing, the data is stored again in the banoffer memory or written into the display memory 5 via the display control circuit 4.

10 is a keyboard equipped with keys for outputting various commands, and its signals are applied to the CPU 8.

The temperature information of the earth's surface measured by the satellite is expressed by the above device in a color corresponding to each temperature, and from the position information of each point obtained separately from this temperature information, the CRT display device 7
The map figure and the temperature at each point are displayed in color on the RT screen, and when the map is not enlarged, it is displayed as shown in FIG. 17, and when it is enlarged, it is displayed as shown in FIG. 18.

The signal processing for obtaining the temperature distribution diagrams shown in FIGS. 17 and 18 is the same as that known in the art, so detailed explanation will be omitted.

In the present invention, the noise removal processing section and the smoothing section for smoothing the boundaries of the mosaic shape are implemented by, for example, a CPU.
8, which will be explained below.

1. Key manual interrupt processing In step S1, the operating key is identified, the menu selected from it is identified, and execution is shifted to various processing routines.

The structure is such that addition/deletion of menu items and transfer of execution to the selection menu can be easily performed using conventional technology.

The various processes in steps S2 to S7 wait again for key human power after the execution process, so the various processes can be executed redundantly. That is, the processes of the noise removal step S8, the smoothing step S9, and the isothermal line processing step SIO can be performed on images received from a satellite as well as on reproduced images received and recorded in the past. Furthermore, noise removal, smoothing, and isothermal processing can be performed simultaneously.

Note that the display memory 5 uses VRAM, and this VRAM
The data used in the CPU is processed in the temporary banoffer memory and the buffer memory 3, and the data processing is as follows.

-The image data has 1024 dots per line, making the total 1024 lines.

- Also, one dot is 8-bit data.

・The top line number is O and the bottom line number is 1023.

- For each line, dot numbers are O at the left end and 1023 at the right end.

・B (0.0): Pixel data address ・There are 2 lines of 1024 donot/l line.

2. noise removal The following method was used for noise removal in this example.

Table l (2) Pay attention to the pixel on which the processing operation is performed and its adjacent pixels.

■The pixel to be processed is E, and the surrounding pixels are shown in Table 1.
As shown in .

■ Arrange the pixels from A to [ arranged as shown in Table 1 in order of decreasing value.

(2) Store the value of the pixel in the middle position as the value after E processing.

■Repeat ■~■ for other pixels.

■When all pixel calculations are completed, the original data is replaced with the processed data stored in memory.

- From the above, the arithmetic processing can be performed for each line from line 1 to line 1022 and from dot 1 to dot 1022.

Next, each steno knob that performs the above calculation will be explained.

In step S21, a processing start line number is set.

Next, in step S22, the subroutine [lLINE] also performs arithmetic processing for (1) line. The operation result data is stored in line 1 of temporary memory.

Next, in step S23, it is determined whether or not there is processed data in line O of the temporary memory.

If L>1, line O of the temporary memory contains the operation result data of line (L-1). / SL・Sofa (L
Since the data in -1) does not need to be used later, it is replaced with the calculation result data. L is the line number of the scanning line for image processing.

Next, in step S24, dot 1 of line O in the temporary memory is
The data of dot 1022 is transferred from the buffer line (L-
1) is transferred from dot 1 to dot l022.

Next, in step S25, the data on the line (L-1) of the buffer is transferred to the line (L-1) of the V-RAM. As a result, the processed lines are displayed on the CRT as the processing progresses.

Next, in step S26, the data on line 1 of the temporary memory is transferred to line O.

Next, in step S27, the line number of the buffer to be calculated next is set.

Next, in step S28, it is determined whether the calculation has been performed on all lines.

Next, in step S29, all line calculations are completed. The calculation result data of the final calculation line (1022) is transferred from the temporary memory to the bath sofa 6.

Next, step S30 is the same as step S25.

The processing of subroutine S22 is as follows.

Note that D is the dot number of the pixel to be processed.

A processing start dot number is set in step S31.

In step S32, the subroutine [CALCU]
Performs arithmetic processing for dots. The calculation result is stored in dot D of line l of the temporary memory.

Set the do noto number to be processed by the steno knob S33.

It is determined at the steno knob S34 whether or not the calculation for one line has been completed.

3. Smoothing Next, an example of a smoothing method for smoothing mosaic-like boundaries that appear prominently when a temperature distribution image is enlarged will be described. That is, in this embodiment, a known smoothing expansion method using estimated value interpolation and supplementation was used.

As shown in FIG. 6, each one pixel A, B, C of the original image
, D using the following formula to calculate the pixel's A l l+ A I1
...A nL B ll + B lt - B nn values are calculated and each pixel A . ~Ann+B. , -Bnn, etc. to create an enlarged screen.

A. ．． =A,B. ,=B,C. ．． =C,D,,=D^,
il=^. ．． +”” ”'X(n-1) n=1.2
．． 3=4nC. −＾11 An+=A++ + ×(n I)
n=1.2.3-Nn - Perform vertical (or horizontal) calculations after all horizontal (or vertical) calculations have been performed.

In FIG. 5, Z is the magnification factor of the image.

In FIG. 5, vertical (
Calculate the number of dots of V) and i(H). (The remainder is discarded.) In step S42, the buffer data in the display area is transferred to the work buffer.

In step S43, the memory is temporarily cleared to O so that O is written in the unnecessary area when storing the calculation result in the buffer.

In steps S44 and S45, the display start address is set to the reference address (B (0.0)) of the area where the processed data is stored so that the progress of the arithmetic processing is displayed on the CRT in the same size as when the processing was specified. , set the magnification to 1x.

In step S46, a buffer address counter for storing data after the calculation is completed is set, and line L=OB (L, O).In step S47, the calculation start line number is set.

Step 348 expands horizontally by one line and stores the result in line l of temporary memory.

In step S49, it is determined whether there is data in line 0 of the temporary memory.

The data on line O of the temporary memory is expanded and stored in the bathtub S50.

In step S51, data on line 1 of the temporary memory is shifted to line 0.

In step S52, the work buffer line number to be processed next is set.

In step S53, it is determined whether all lines have been completed.

In step S54, the data of the last horizontally enlarged line remains in line O of the temporary memory, so it is transferred to the buffer.

In step S55, 354 data are transferred to the display memory 5 and displayed.

In step S56, the buffer and display memory 5 still have areas where unprocessed data remains, so they are cleared.

Next, the subroutine of step S42 will be explained with reference to FIG.

In this subroutine, buffer data in the display area is transferred to the work buffer.

H is the number of display dots in the original data (buffer data) in the horizontal direction ■ is the number of display dots in the original data (buffer data) in the vertical direction LO is the original data line number of the display start pixel Do is the original data of the display start pixel It is a dot number.

In step S61, the line number initial value is set.

The line counter is cleared in step S62.

In step S63, dot number initial values are set.

The dot counter is cleared in step S64.

Transfer the data using the steno knob S65, and set the dot number to +l (next dot set) using the steno knob S66.

In step S67, the number of transferred dots is counted and the step number is 36.
At 8, it is determined whether the l line is finished.

In step S69, the line number is increased by 1 (next line set).

Add 1 to the line counter using the stenop 370, and proceed to step S7.
1 determines whether all lines are finished.

FIG. 8 shows details of subroutine H ZOOM.

In step S72, the calculation start number is determined.

In step S73, a difference value between dots during enlargement is calculated. N
: Line number, Z: Enlargement magnification Set the initial value of the enlargement calculation counter in step S74.

In step S75, the enlarged pixel value is calculated (rounded off).

In step S76, the data is stored in line l of the temporary memory.

In step S77, the number of enlargement calculations is counted.

In step 378, it is determined whether the original data for one pixel has been completed.

Set to the next pixel (with original data) in step S79.

In step S80, it is determined whether the enlargable pixel calculation is completed.

Number of H2 horizontal original image dots In step S81, the last pixel is stored in temporary memory.

FIG. 9 shows details of subroutine V ZOOM.

In step S82, the calculation start dot number is set.

In step S83, a difference value between dots during enlargement is calculated. 2
: Enlargement magnification T (◯, ◯) 2 Temporary memory address In step S84, the enlargement calculation counter is initially set.

In step S85, the enlarged pixel value is calculated (rounded off).

In step S86, the calculated pixel value is stored in the buffer.

In step S87, the number of enlargement calculations is counted.

In step S88, it is determined whether the processing for l pixels has been completed.

In step S89, the next pixel is designated.

In step S90, it is determined whether one line is finished.

By the above-described noise removal processing, the noise image shown by point Q in FIG. 18 is removed from the distribution map displayed on the CRT display device 7. Therefore, it is no longer confused with point R indicating an isothermal line, for example, and the screen becomes easier to see.

Further, by the smoothing process, the boundaries of the mosaic-shaped temperature distribution as shown in FIG. 18 can be expressed as smooth lines.

Next, creation of isothermal lines will be explained.

The buffer memory 3 stores the temperature level of each pixel as a value obtained by quantizing temperature information into one of 0 to 255 levels. These temperature levels are grouped into a plurality of levels, for example, group G with 18 levels. ,G,,...
, G1, appropriate multi-stage threshold L
. , L1, ..., L18.

The image data in the buffer memory 3 is copied to the display memory 5 (hereinafter referred to as V-RAM 5). The display color of each level is determined and the color data is written in the runokup table 6.

The pixel data value in the buffer memory 3 shown in FIG. It is stored as shown in Figure 11b.

Note that in the case of the ■th line or the final line, 0 is replaced with pixel data in the buffer. In the case of the lth dot or the final dot of each line, O is replaced with the pixel data of the buffer. Then, using the temporary pixel values of surrounding pixels B, D, F, and H around one pixel, for example, pixel E in Table 1, the Laplacian calculation value E° for pixel E is determined by the following formula.

E'=-B-D+4E-F-H Then, if E°≦O, the corresponding pixel data in the buffer memory 3 is replaced with O. As for the pixel E゜〉0, the original pixel data 14, to, and 21 remain as data in the buffer memory 3, and all other pixels become O, as shown in FIG. 11(d).

The data in the buffer memory 3 rewritten as described above is copied to the I-RAM 5.

Then, isothermal lines are displayed on the CRT display screen of the CRT display device 7 according to the data written in the V-RAM 5.

Note that in the above process, the display color group numbers are numbered in descending order. The threshold level (lowest level of each group) setting value for each group is stored in a memory addressed by its group number.

Each threshold value is as shown in Table 2.

Table 2 Next, the above processing will be explained in more detail.

L is the image line number to be processed.

In step S91, a processing start line number is set.In step S92, a subroutine [lLINET] performs calculation processing for l line. The operation result data is stored in line l of temporary memory.

In step S93, it is determined whether there is processed data in line 0 of the temporary memory. If L>O, the operation result data of line (L-1) exists in line O of the temporary memory.

Since the data on line (L-1) is unnecessary for the calculations on and after line (L+1), it is replaced with the calculation result data.

At step S94, data on line O of the temporary memory is transferred to line (L-1) of the buffer.

At step S95, the data transferred to the vanofa memory 3 is transferred to the same V-RAM 5. Thereby, the CRT display of the processed line is performed as the processing progresses.

At step 396, data in line 1 of temporary memory is transferred to line 0.

In step 397, the line number of the buffer memory 3 to be calculated next is set.

In step S98, it is determined whether all line calculations have been performed.

In step S99, all line calculations are completed. The calculation result data of the final calculation line (line 1022) is transferred from the temporary memory to the buffer memory 3.

In step S100, the same effect as in step S95 is performed.

At step SIOI, all data in line 1023 of the buffer is set to 0. This means that all the dots on the outermost periphery of the image have become O's.

In step S102, the above data is transferred to the V-RAM 5 and displayed.

Details of subroutine 11, INET in FIG. 12 are shown in FIG. 13.

D is the dot number of the pixel to be processed.

In step Sill, the temporary memory is once cleared to 0 in order to set the outermost dot of the image to O. Thereafter, in this routine, no data other than 0 will be written to dot O and dot 1023 in line 0 of the temporary memory.

In step Sll2, a calculation start dot number is set.

In step 3113, the subroutine [C A L CU
T] performs Laplacian calculation processing for one pixel. The calculation result is stored in dot D of line l of the temporary memory.

In step S114, the dot number of the next pixel to be processed is set.

In step S115, it is determined whether or not the calculation for the {circle around (2)} line has been completed.

FIG. 14 shows the subroutine CALCUT.

B(○,○) indicates a pixel address in the buffer.

T(0,O) indicates the pixel data address of the operation result temporary memory.

L and D are the line number and dot number of the processing pixel.

In step S121, work memories M(1) to M(5
) reads the pixel to be processed and the pixel data above, below, left and right of it.

In step S122, M(1) to M(5) are converted into temporary pixel values based on display color group numbers. (subroutine[
COLOR N]) In step S123, Laplacian calculation is performed.

In steps 8124 to S126, if the calculation result is greater than 0, the original pixel data is read from the buffer and the calculation result is stored in the temporary memory as processed data. If the calculation result is less than or equal to O, 0 is stored in the temporary memory as processed data.

M(1) to M(5) in step S121 are pixel data regarding pixels arranged as shown in FIG.

FIG. 16 shows details of the subroutine COLOR N.

In this figure, G(N,) is the lowest level of display color group N, and M(N,) is N,=l~5. This is pixel data to be replaced with the display color group number.

Note that the method for receiving temperature information from the satellite is not limited to the one shown in FIG. 1, and various other methods can be used. Furthermore, various Laplacians can be used to create the isothermal diagram.

As described above, in the present invention, it is possible to remove noise from images transmitted from a satellite and display the images, but generally noise removal processing requires a relatively long processing time. Therefore, it is useful to reduce the time of this process.

A specific example is shown below.

The data received from the satellite is 1024 dots vertically x 102 horizontally.
Although the area is 4 dots, the number of display pixels on the CRT screen is 48.0 dots vertically x 464 dots horizontally. Furthermore, the area that the user actually needs is approximately 120 dots vertically x 120 dots horizontally within the received data, and the area is enlarged and displayed so that almost the entire area fills the CRT screen. .

Incidentally, the processing time for image data is approximately proportional to the number of pixels to be processed. Therefore, if only the areas necessary for the user are processed, the required processing time can be significantly reduced. The necessary area is approximately the area displayed on the CRT, and this area can be easily known from the display control circuit. Therefore, the processing area is C
By selecting the area displayed on RT or a slightly larger area, the processing time can be significantly reduced compared to processing the entire area.

This method is especially effective in noise removal processing, which requires rearranging data and requires a lot of processing time.

To carry out the above processing, for example, in the apparatus shown in FIG. 1, a part of the signal stored in the buffer memory 3 is extracted, and the display control circuit 4 performs, for example, noise removal processing, and the processed signal is processed. It is sent to the buffer memory 3 and the display memory 5 and stored therein.

More specifically, the buffer memory 3 and the display memory 5, which is a V-RAM, have a one-to-one correspondence in each pixel. That is, if the address of a specific pixel on the V-RAM is known, the address of the same pixel on the buffer memory 3 can be specified.

Both V-RAM and Vanofa are expressed as distances from the reference pixel 100. Therefore, the address of pixel 100 may be added to that value.

On the other hand, the image display on the CRT is performed by setting the address of the display starting point 101 and the display magnification N in the display control circuit 4 shown in FIG.

The size of the processing area during image processing is set to 21 (in the X and Y directions) of the display area, taking into consideration scrolling after processing and the like.

If the address of the display starting point 101 is B1 (XB, Y.), then the address of the processing starting point B゜ is X'
a Y' If the a co-operation result is smaller than O, set it as O.

The address of the processing end point C° is, however, X'. If both +Y'c are larger than l023, l
023.

It is required as.

Since Xa, Y6, and N are all stored in the work memory area of the main CPU 8 and are known, from the above formula, B
', C' can be easily obtained.

From the above, calculation processing of image data (noise removal, etc.) is B.
This is done for the area whose vertices are the two points ', C''.

That is, You can do it against them.

Effects of the Invention As described above, according to the present invention, in the surface temperature distribution diagram,
Since isotemperature lines are displayed, it is easy to determine tides and currents from the isotemperature lines on the sea surface.

Furthermore, if the isotemperature lines are displayed in different colors depending on the temperature, you can also know the temperature. Even if the Laplacian result is smaller than O, two lines can be drawn by leaving the original pixel data, and the temperature distribution can be easily determined.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a flowchart showing the processing flow of the main part of the embodiment of FIG. 1, and FIGS. 3 and 4 are flowcharts showing the operation of the noise removal section. , FIG. 5 is a diagram showing an example of smoothing processing,
6 to 9 are flowcharts showing an example of smoothing, FIG. 10 is a diagram showing an example of temperature level grouping, FIGS. 14 and 16 are flowcharts showing the process for displaying isothermal lines,
Figure 15 is a diagram showing the relationship between pixels in the flowchart of Figure 14, Figures 17 and 18 are diagrams showing examples of display, Figure 19 is a detailed diagram of the buffer memory, and Figure 20 is the display memory. FIG.

Claims (4)

[Claims] (1) A display device that receives surface temperature information measured by a satellite and transmitted from the satellite, and uses this surface temperature information to display temperature in units of pixels of a predetermined size by color or density to display a temperature distribution map. The image processing device shown above includes a temperature boundary detection means for detecting a pixel located on a temperature boundary where two pixels having different temperatures are adjacent to each other, and a pixel located on the temperature boundary detected by the detection means is displayed. 1. A surface temperature display device comprising: display control means for creating isothermal lines as states. (2) Claim (1) further comprising a noise removing means for removing noise that would appear on the display screen, and a smoothing means for correcting a step-like portion that occurs on the temperature boundary into an apparently smooth line. ) surface temperature display device. (3) The temperature boundary compares the temperature information of multiple pixels surrounding one pixel with a predetermined threshold, and if the temperature information is above the threshold, it is set to 1, and if it is below, it is set to 0. As the temperature information of the surrounding pixels, temporarily allocate it, calculate the Laplacian calculation value for the above one pixel according to a predetermined calculation formula, and if the calculation value is equal to 0 or smaller than 0,
2. The surface temperature display device according to claim 1, wherein the temperature information of the one pixel is set to 0, and if the calculated value is greater than 0, the first temperature information of the one pixel is used. (4) A buffer memory that stores digitized data of the received image signal, a display memory that stores display data, and extracts some data from the buffer memory and processes that part of the data. 2. The surface temperature display device according to claim 1, further comprising control means for returning the processed data to the original position in the buffer memory and also writing the processed data to the display memory.