Image processing device, radar apparatus, image processing method and image processing program

Patent metadata

Field	Value
Publication number	US-9575173-B2
Application number	US-201214363760-A
Country	US
Kind code	B2
Filing date	Dec 4, 2012
Priority date	Dec 9, 2011
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

Abstract

An image processing device which generates an image where a target object can be discriminated from an object other than the target object. An image processor ( 15 ), for echo signals read from a sweep memory ( 14 ), calculates a ratio of echo signals indicating a predetermined level or higher among the echo signals of a predetermined number of samples, and generates image data having a display element according to the calculated ratio. This ratio indicates a lower value for an object more isolated and a higher value for an object existing as a larger mass. The image processor ( 15 )acquires color values according to the calculated ratio. Since the target object, such as a ship, is an isolated object and the ratio becomes low, the color values indicate red, and since inland is an object existing as a large mass and the ratio becomes high, the color values indicate green.

First claim

The invention claimed is:

1. An image processing device including an image data generating module configured to generate image data, comprising:
a sample data output unit configured to receive echo signals and output data of respective samples obtained by discretizing the echo signals;
a target selecting module configured to select, among the samples, samples within a predetermined range in a sample area;
an extracting module configured to extract, among the samples determined by the target selecting module, samples that satisfy a predetermined reference value; and
a ratio calculating module configured to calculate a ratio of the number of the extracted samples with respect to the number of the samples within the predetermined range, wherein
the predetermined range is a range in an azimuth direction and/or a distance direction,
satisfying the predetermined reference value corresponds to having a value higher than the echo signals resulting from background noise,
the image data comprises a plurality of pixels, and
the image data generating module determines one of three or more display modes for each pixel of the image data based on the ratio and the predetermined reference value.

2. The image processing device of claim 1 , wherein the target selecting module selects, among the sample data, the samples within the predetermined range centering on a certain observed sample.

3. The image processing device of claim 1 , wherein the ratio calculating module calculates the ratio for all samples of the echo signal.

4. The image processing device of claim 1 , wherein the image data generating module generates the image data having color values according to the ratio.

5. The image processing device of claim 4 , wherein the image data generating module determines hue and chroma according to the ratio, determines brightness based on a level of the echo signal, and converts the determined hue, the determined chroma and the determined brightness into the color values.

6. The image processing device of claim 1 , further comprising a low density data generating module configured to generate low density data in which a sample density of the echo signals is reduced, and
wherein the ratio calculating module calculates the ratio based on the low density data.

7. The image processing device of claim 5 , further comprising a low density data generating module configured to generate low density data in which a sample density of the echo signals is reduced,
wherein the ratio calculating module calculates the ratio based on the low density data,
wherein the image data generating module determines the hue and the chroma according to the ratio calculated based on the low density data, and determines the brightness based on the level of the inputted echo signal, and
wherein the image data generating module relates the determined hue and the determined chroma to the respective samples of the echo signals before a reduction, and converts the hue, chroma and brightness into the color values.

8. The image processing device of claim 1 , wherein the extracting module reduces the sample number of all the samples within the predetermined range selected by the target selecting module, and extracts the samples satisfying the predetermined reference value among the reduced samples, and
wherein the ratio calculating module calculates the ratio by having the number of the reduced samples as the samples within the predetermined range.

9. The image processing device of claim 1 , wherein the image data generating module performs cross-fade processing to smooth the image data.

10. The image processing device of claim 1 , further comprising a Doppler speed detecting module configured to detect a Doppler speed of each sample,
wherein the extracting module extracts a sample of which Doppler speed is a predetermined speed or higher, as the sample satisfying the predetermined reference value.

11. A radar apparatus, comprising:
the image processing device of claim 1 ;
a transceiver configured to discharge electromagnetic waves around the radar apparatus, receive the echo signals reflected on respective target objects, and input them to the sample data output unit; and
a display unit configured to display an image including the target objects based on the image data generated by the image data generating module.

12. An image processing method for generating image data implemented at least in part on a display device, comprising:
receiving, with a receiver, echo signals with analog values, corresponding to an image pixel, from an antenna;
converting the received echo signals into discretized echo signals, corresponding to the image pixel, with digital values via an A/D converter;
outputting the discretized echo signals into memory;
causing a processor of the display device to:
select, among the discretized echo signals, discretized echo signals within a predetermined range in a sample area, the predetermined range being a range in an azimuth direction and/or a distance direction;
extract, among the discretized echo signals within the predetermined range, discretized echo signals that satisfy a predetermined reference value, wherein satisfying the predetermined reference value corresponds to having a value higher than the echo signals resulting from background noise;
calculate a ratio of the number of the extracted discretized echo signals with respect to the number of the discretized echo signals within the predetermined range, and
determine one of three or more display modes for each pixel of the image data based on the ratio for image data comprising a plurality of pixels, and

displaying the image data on a display of the display device.

13. An image processing program, stored on a non-transitory computer readable medium, implemented by an image processing device, the program executed at least in part by a processor of the image processing device to cause the image processing device to execute an image data generating step, comprising:
a sample data output step of receiving echo signals from an antenna with a receiver, converting the received echo signals into discretized echo signals with an A/D converter, and outputting data of respective discretized echo signals into memory;
a target selecting step of selecting, among the discretized echo signals, discretized echo signals within a predetermined range in a sample area with the processor;
an extracting step of extracting, among the discretized echo signals selected by the target selecting step, discretized echo signals that satisfy a predetermined reference value with the processor;
a ratio calculating step of calculating a ratio of the number of the extracted discretized echo signals with respect to the number of the discretized echo signals within the predetermined range with the processor,
wherein the image data generating step includes determining one of three or more display modes for each pixel of the image data based on the ratio for image data comprising a plurality of pixels,
the predetermined range is a range in an azimuth direction and/or a distance direction,
satisfying the predetermined reference value corresponds to having a value higher than the echo signals resulting from background noise, and
displaying the image data on a display device.

Assignees

• Furuno Electric Co

Inventors

• Nishiyama Koji

Classifications

• G06T11/10

  Texturing; Colouring; Generation of textures or colours (retouching, inpainting or scratch removal G06T5/77) · CPC title

• G01S13/937

  of marine craft · CPC title

• G01S7/062

  in which different colours are used · CPC title

• G01S7/046 Primary

  using an intermediate storage device, e.g. a recording/reproducing device · CPC title

• G09G5/02

  characterised by the way in which colour is displayed {(details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607)} · CPC title