JPH01129367A - Picture processor - Google Patents

Abstract

PURPOSE:To attain a filter processing without lowering a processing speed even when the number of picture elements constituting a picture is large by setting a ROI at the arbitrary position of the picture and applying the filter processing only in this ROI. CONSTITUTION:Only the ROI set to the picture displayed on a display is filtered and this result is displayed on the arbitrary position internally or externally of the ROI. When generally, the filter processing is applied to display the picture, an area desired to be observed may be substantially a part of the picture in most cases. Accordingly, in such a way, the ROI is set to the area to be filtered. Thereby, even when the number of the picture element is large, the filter processing can be applied without lowering the processing speed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an image processing device that filters an image and displays it on a display.

(Prior Art) For example, an X-ray CT device known as a medical device measures the X-ray absorption coefficient of a subject as a CT value, reconstructs the distribution of this CT value as a grayscale image, and displays it on a display. It is designed to be used for diagnosis. When displaying an image in this way, - depending on the purpose, a part of the image may be emphasized as shown in Figure 3(a), or the entire image may be smoothed as shown in Figure 3(b). Filter processing is performed. Such filter processing is performed on all pixels constituting the image, and image processing is performed by multiplying the pixels by arbitrary filter coefficients.

(Problems to be Solved by the Invention) However, when performing such filter processing, there is a problem that time is wasted in image processing when the number of pixels forming an image is large. If we try to speed up this process, it is necessary to prepare large-scale hardware using a special decoder circuit, which inevitably increases costs.

The present invention was made in response to the above circumstances.
It is an object of the present invention to provide an image processing device that performs filter processing only on necessary areas.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention is characterized in that an ROI is set at an arbitrary position in an image and filter processing is performed only within this ROI. It is something.

(Function) ROI set in the image displayed on the display
This result is filtered only within the ROI or R
Displayed at any position outside the OI.

Generally, when displaying an image after performing filter processing, the area to be observed is often only a portion of the image. Therefore, by setting the ROI in the region to be filtered in this manner, filtering can be performed without reducing the processing speed even when the number of pixels is large.

(Embodiment) FIG. 1 is a block diagram showing an embodiment of the image processing device of the present invention. Image memory 1 is for storing an original image obtained by CTifft shadow, and this original image is stored in area A. be done. The processor 2 controls the entire device and performs desired filter calculations, and is composed of a dedicated microprocessor, such as a 16-bit MPU, and the filtered image is stored in another area B of the image memory 1. Stored. The graphic controller 3 is used to cause the bit plane memory 7 to display graphics at high speed by utilizing the bit map display function. The image processor 4 sets a desired window conversion condition consisting of two parameters, a window level and a window width, for the image stored in the image memory 1, and performs a window conversion process against this condition. This is for storing the results in the frame memory 6. The frame memory 6 stores an image subjected to window conversion processing as a display image, and this image is displayed on a CRT display 9 after being D/A converted by a D/A converter 8.

The ROI input device 5 is composed of, for example, a digitizer, a mouse, a tracker ball, etc., and when an image is displayed on the display 9, an ROI (region of interest) is set on the image by this operation, and the ROI is set by the graphic controller. With the function 3, an arbitrary shape such as a quadrilateral, two circles, an ellipse, etc. can be displayed at high speed based on the settings. Further, this ROI is configured to be movable to any position, and also configured to be freely enlarged and reduced.

When the ROI is set in this manner, the filter processing is performed by the processor 2 inside the ROI.

Next, the operation of this embodiment will be explained.

As shown in FIG. 2, the original image stored in area A of the image memory 1 is taken out by the image processor 4, subjected to window conversion processing under optimal window conversion conditions, and then stored in the frame memory 6. This angle of view is displayed on a display 9 via an A converter 8. The above window conversion processing process is shown as the first time by a solid line.

Next, when ROllo is set at an arbitrary position on this image by the ROI input device 5, this ROllo is set in the bit plane memory 7, and then the inside of this ROl 10 is filtered by the filter operation by the processor 2. be done.

As is well known, filter processing is performed using three methods targeting desired pixels.
×3 or 5×5 plane filter calculations are performed, and the filtered image within the ROI 10 is stored in another area B of the image memory 1.

Next, the image that has been filtered and stored in another area B of the image memory 1 is taken out again by the image processor 4, subjected to window conversion processing under similar window conversion conditions, and then stored in the frame memory 6. At the same time D/A
Via a converter 8 this image is displayed on a display 9. In this case, since the original image that was first subjected to window conversion processing and stored in the frame memory 6 is displayed on the display 9, the image in the RO 110 that has been filtered and overlapped with this original image is displayed. become. The above window conversion processing process is shown as a second time by a dotted line.

In the case where the image processor 4 performs window conversion processing as described above, when the image stored in the image memory 1 is input to the image processor 4, the processor 2
With this, it is possible to create and add a flag that turns a bit on or off to the image data. According to this method, it is possible to select only those input images whose CT values are in a specific range after window conversion processing and store them in the frame memory 6, so that only the part to be observed can be selected and displayed. 9 can be displayed.

The ROI can be moved to any position on the image by operating the ROI input device 5, and the size of the ROI can also be freely enlarged or reduced. ROI 10
When the image is moved or enlarged or reduced, the original image is first subjected to window conversion processing, and then the ROI is
Window conversion processing in 10 is performed. Also ROI
If the position of 10 does not move and only the filter coefficients for filter calculation are changed, window conversion processing within RO 110 may be performed. The filtered image within the ROI can be displayed at any position within or outside the ROI.

According to this embodiment, filter processing is performed only on the inside of the ROI, not on image pauses, so that even if the number of pixels is large, filter processing can be performed without reducing the processing speed. As a result, it is possible to perform normal program processing without the need for a special arithmetic circuit.
The purpose can be fully achieved by using PU etc. In addition, the location and size of the ROI can be arbitrarily selected.
It has great practical value because smooth filter processing can be performed.

[Effects of the Invention] As described above, according to the present invention, since an ROI is set and filter processing is performed only within this ROI, the processing speed can be reduced even when the number of pixels forming an image is large. Filter processing can be applied without any need for filter processing.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the image processing apparatus of the present invention, FIG. 2 is an explanatory diagram of the operation of this embodiment, and FIG. 3(a),
(b) is a schematic diagram illustrating an example of filter processing. 1... Image memory, 2... Processor, 4
... image processor, 5... ROI input device,
6...Frame memory. Agent: Patent Attorney: Takeshi Kondo (G) Figure 3

Claims (1)

[Claims] In an image processing device that filters an image and displays it on a display, R is used to set an ROI at an arbitrary position in the image.
An image processing apparatus comprising: an OI input means, a means for filtering an image within the ROI, and a means for displaying the filtered image at an arbitrary position.