JPS6116984B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for highlighting an arbitrary area of an image in a color image display device that displays shading figures by making the shading changes correspond to colors.
Emphasizes color changes in only a part of the image that is of interest,
Other parts are used to highlight arbitrary areas in the image by suppressing color changes and making the image blurry.

Conventionally, in this type of display, in order to clarify the contrast of the entire image before displaying the image, the density values are linearly expanded and converted using the maximum and minimum density values of the entire image. , this was done to display.

However, when targeting the density value of the image itself, the absolute value of the density value is converted, so if you read the density value of the specified pixel from the display memory while looking at the display screen, you will only get the converted data. I can't. Moreover, when expanding the density value of only a part of the image as a preprocessing before display, the coordinates of the designated area must be determined and input offline, which has the disadvantage that it takes too much time. There is.

It is an object of the present invention to eliminate these drawbacks in conventional displays and to extend the density values within an image display device such that the absolute value of the density values does not change.

Another object of the present invention is to normalize the density values only within an arbitrary partial area of the image specified by the operator while looking at the screen, and to emphasize color changes compared to other areas. Therefore, the purpose is to clearly display a part visually.

Still another object of the present invention is to enable the operator to select a target area and observe the display results in real time.

According to the present invention, a color image display device that sequentially reads image information stored in an image memory from the image memory and displays it as a color image via a color converter to assign a color corresponding to the density value. a region specifier for specifying one or more boundaries of an arbitrary shape in an image memory; and a maximum value and minimum value detector for determining the maximum and minimum values of an arbitrary density range of pixels within the one or more regions. a readout address controller that controls readout address changes from the color converter for pixels within the area according to the maximum value and minimum value, and A color image highlighting display device that highlights pixels in any color is obtained.

Next, details of the present invention will be explained with reference to the drawings.

FIG. 1 shows an embodiment of a display device according to the present invention. In the figure, 1 is a display medium such as a cathode ray tube, and 2 is a refresh memory having the number of pixels corresponding to the display screen on the display medium. , an intensity value is stored for each pixel, usually consisting of several bits. 3 is an address register that stores the X and Y coordinates of the starting point of the rectangular area to be highlighted, and 4 is a △X, △Y register that stores values indicating the width of the rectangular area in the X and Y directions. Setting of values is accomplished at terminal 20 by an external coordinate input device such as a light pen or tablet pen. 5 is a timing controller for shifting the image data stored in the refresh memory 2 in parallel and selectively taking out only the pixels within the rectangular area; 6 is a timing controller for shifting the image data stored in the refresh memory 2 in parallel; Maximum and minimum value detectors for determining values and minimum values; 7 a read address controller for controlling read address changes from the color converter 8 according to the maximum and minimum values for pixels in the area; 8; 9 is a color converter that allocates colors according to the shading of pixels, and 9 is a digital/analog converter that converts the digital signal output of the color converter 8 into analog three primary color signals (red, green, blue) and supplies them to the display device 1. It is a vessel. Now, via the signal terminal 20,
Assume that the starting point coordinates (m, n) of a rectangle are stored in the address register 3 and its widths k, l are stored in the ΔX, ΔY register 4 from the outside. In normal display, the image data already written in the refresh memory 2 is sequentially read out by an external input device, and is given to the read address controller via the signal line 201, and its density value is unchanged. This becomes the read address of the color converter 8, and a color code signal corresponding to the density value is read out from the color converter 8. These three primary color signals are converted into analog signals by the digital/analog converter 9 and displayed on the display device 1. Here, it is assumed that image data is written in the refresh memory 2 in advance.

As an example, if the image data is 6 bits,
The color converter 8 has 64 types of three primary color components (color codes) indicated by address numbers from 0 to 63rd. Each color component consists of a 6-bit code. Since the color converter 8 is composed of a random access memory, when reading out a color code, by giving an address value to a readout signal line (not shown), the color code stored at the specified address can be read out. . It is assumed that these color codes are stored in advance.

Now, let the arbitrary area in the refresh memory 2 be one rectangular area, and the starting point coordinates of that area (m, n)
and the widths k and l of the area are respectively connected to the signal line 2 from the outside.
0 to address register 3 and △X, △Y
Assume that the address is given to address register 4. A method in which the timing controller 5 quickly obtains the maximum and minimum density values of pixels within a rectangular area using these values and stores the values in the maximum and minimum value detectors 6 has already been disclosed in a patent application filed in 1972. Since it is described in detail in Japanese Patent No. 83299, "Image Enhancement Display Device," it is omitted here, and it is assumed that the maximum and minimum density values of the specified area have already been determined.

Next, with reference to FIG. 2, an embodiment will be described in which a designated area is highlighted as a color image using the maximum and minimum values. Components that are the same as those in FIG. 1 are given the same numbers. In conventional contrast enhancement, the maximum and minimum values of the original image density values are used, with the maximum value (max) set to 63 and the minimum value (min) set to 0, during which the original data can be expanded linearly or non-linearly. However, this method changes the density value itself of the original data, which may be inconvenient for subsequent processing. Therefore, in the present invention, since it corresponds to the maximum value of the original data, the max number of the color converter is set to the 63rd color code, which corresponds to the minimum value.
By making the min-th color code appear to be the 0-th color code and dividing this in a linear or non-linear manner, color display equivalent to contrast enhancement of the original data can be achieved without changing the density value of the original data. can be made to perform. For simplicity, consider the case where the maximum value and minimum value are linearly divided. The density value of the pixel in the rectangular area is expressed as X _O (min
X _O max), then the conversion is performed as shown in the following equation.

X _N =X _O -min/max-min x A(1) X _N is the density value after conversion, and corresponds to the address number (0 to 63) of the color converter. A is the maximum density value after conversion, and usually A is a 4 to 8 bit value.
The external terminal 21 can provide as many front areas as there are areas.

The maximum value and minimum value are stored in the maximum value and minimum value detector 6 as many as the number of regions, and are connected to signal lines 61 and 61, respectively.
62, the values corresponding to the regions are sequentially given to the subtractor 71 by the timing controller 5, where
max-min is calculated, and the result is sent to divider 7.
A/
(max-min) is determined, output as a constant, and stored in register 78. On the other hand, the minimum value of the signal line 62 is also applied to the subtracter 74. When the constants have been stored in the register 78, the timing controller 5 reads out the pixels in the memory 2 onto the signal line 201 using a normal refresh rate in order to display the pixels on the display device 1. At this time, the timing controller 5 determines whether the read pixel is inside or outside the rectangular area using the same procedure as the maximum value and minimum value detection, and if it is within the area, outputs "1" on the signal line 51, If it is outside the area, "0" is output, and a timing signal is sent to the signal line to read out the maximum value already stored in the maximum value/minimum value detector 6 and the calculation result of the register 78 corresponding to that area. If the read pixel output to 52 is within the area, AND gate 76 opens and provides image data to subtracter 74 . The subtracter 74 is X _O −
min is calculated and output to the multiplier 73. The multiplier is (1)
The equation X _N is determined and output to the OR gate 75. At this time, the AND gate 77 is not open, so the output signal line 202 of the OR gate 75 is connected to the read address signal line of the color converter 8.
The color code of the address corresponding to _XN is read out. Conversely, if the pixel read from the memory 2 is outside the area, "0" is output to the signal line 51, so the density value of the read pixel is determined by the AND gate 76.
Since the signal is output onto the signal line 202 via the AND gate 77 and the OR gate 75 without passing through the signal, a normal color conversion display is performed.

As described above, according to the present invention, any area within the display screen can be monitored while the display screen is being monitored.
By giving instructions using a coordinate input device such as a light pen or tablet left, only the image within the area can be highlighted in real time, increasing the display effect. Furthermore, since the initially stored density value of a pixel can be highlighted without any change, it is also effective in handling the density value itself.

Although this embodiment has been described using a rectangular area as an example to simplify the explanation, the present invention is not limited to this and can be easily expanded to other shapes. A method of scanning a closed area defined by line figures of arbitrary shape in a raster manner and determining its boundaries is described, for example, in A. Rosenfeld's “Picture Processing by
Computer”, Academic Press (1969), and can be easily applied to the case of arbitrary shapes.Also, even if there is not one closed region but multiple closed regions, address registers 3 and 4, maximum value, minimum value This is possible by expanding the maximum concentration values from the detector 6 and the external terminal 21 by the number of regions and by expanding the function of the timing control 5.Concentration conversion is performed by linear conversion as shown in equation (1). As an example,
This can also be done as a non-linear transformation in which the assignment of color codes is changed for a certain density range. The density conversion does not have to be executed at the time of pixel readout, but may be calculated in advance and made into a table, and the table may be referred to at the time of readout. It is also possible to conversely reduce the contrast within the region by externally instructing the upper and lower limits of the maximum and minimum values.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of a color image highlighting display device according to an embodiment of the present invention, and FIG. 2 is a diagram illustrating the operation of changing the read address of the color converter inside and outside the highlighted display area. In the figure, 1 is a display medium, 2 is a refresh memory, 3 to 4 are address registers, 5 is a timing controller, 6 is a maximum value/minimum value detector, 7 is a read address controller, 8 is a color converter,
9 indicates a digital/analog converter.

Claims (1)

[Claims] 1. A coloring system in which image information stored in an image memory is sequentially read out from the line memory and displayed as a color image via a color converter in order to assign a color corresponding to the density value. In an image display device, an area designator that specifies one or more boundaries of an arbitrary shape in an image memory, and a maximum value that determines a maximum value and a minimum value of an arbitrary density range of pixels within the one or more areas; a minimum value detector; and a read address controller that controls read address changes from the color converter for pixels within the region according to the maximum value and the minimum value, A color image highlighting display device characterized by highlighting pixels outside a region in an arbitrary color. 2. The scope of claims in which the area designator is comprised of an address register that stores the starting point coordinates of a rectangular area, and △X, △Y address registers that store values indicating the width of the rectangular area in the X and Y directions. The color image highlighting display device according to item 1. 3. The color according to claim 1 or 2, wherein the maximum value and minimum value detector detects the maximum value and minimum value in an arbitrarily specified range within the absolute maximum density range of the stored pixels. Image highlighting device. 4. Claims 1 to 3, wherein the read address controller reads out the color code of the color converter so as to linearly or non-linearly expand the density of pixels in the corresponding area using the maximum value and the minimum value. color image highlighting device.