JP5537048B2 - Image display apparatus, image display method, imaging apparatus, and imaging apparatus control method - Google Patents

Description

  The present invention relates to a technique for displaying a waveform of an input signal level.

  Conventionally, when photographing with a camera or a video camera, it is determined whether or not the entire image and the main subject are properly exposed, and exposure adjustment is performed if necessary. At the shooting site, the output signal of the camera is connected to a device (waveform monitor) that can monitor the waveform, and for example, the brightness level distribution is displayed as a waveform to check the exposure of the entire image. Some cameras and video camera bodies are equipped with a function for calculating a histogram representing the frequency distribution of luminance from the luminance of the image and displaying the luminance level distribution of the image in a graph. The photographer can confirm the exposure by viewing such a graph displayed together with the image on the display device.

  However, in the waveform display and histogram display for the entire image, there is a problem that it cannot be identified where the signal level corresponding to the main subject region of interest in the same screen corresponds to the waveform indicating the luminance distribution. On the other hand, Patent Document 1 proposes a technique for simultaneously displaying an image area of interest and a histogram in association with each other so that they can be identified during histogram display.

JP 2008-172732 A

  However, in the technique described in Patent Document 1, although the correspondence between the position of the display image and the waveform of the luminance distribution is displayed on the display screen, the positions do not match. For example, as shown in FIG. There are cases where the position of the subject and the position of the luminance distribution are misaligned on the left and right. Therefore, there is a problem that it is difficult to confirm particularly when there are a plurality of attention areas.

  The present invention has been made in view of the above-described problems, and an object thereof is to make it possible to easily display an exposure level corresponding to a region of interest of a display image on a display screen.

In order to solve the above-described problems and achieve the object, an image display apparatus according to the present invention includes an image input unit for inputting an image signal, and a relationship between a position and a signal level in a predetermined direction of the input image signal. Waveform generating means for generating a waveform representing the image, area specifying means for specifying a predetermined area of the image signal, display means for displaying the image signal and the waveform on a display device, and specified by the area specifying means And a control means for controlling the display means so as to change the display method of the waveform of the signal level included in the area and the other area.

  According to the present invention, the exposure level corresponding to the attention area of the display image can be easily displayed on the display screen.

It is a figure which shows the basic composition of the image display apparatus in the 1st Embodiment of this invention. It is the schematic of the image processing control part in 1st Embodiment. It is an image figure of the waveform display in 1st Embodiment. It is the schematic of the image processing control part in 2nd Embodiment. It is a figure which shows the color table table | surface in 1st Embodiment. It is an image figure of the conventional histogram display.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a diagram showing a configuration of an image display apparatus according to the first embodiment of the present invention.

  In FIG. 1, an image display apparatus 100 includes an image input unit 101, an image processing control unit 102, an image display unit 103, a format control unit 104, a recording / reading unit 105, a removable recording medium 106, An area designating unit 107 and an operation unit 108 are provided.

  The image input unit 101 is an imaging unit configured with, for example, a plurality of lenses and a CCD (Charge-Coupled Device). The image (video) input by the image input unit 101 is subjected to image processing by the image processing control unit 102 and displayed by the image display unit 103 configured by a liquid crystal panel.

  The image processed image is converted into a recordable format by the format control unit 104, and is recorded on the recording medium 106, which is a recording medium, by the recording / reading unit 105. The image recorded on the recording medium 106 is read by the recording / reading unit 105 and converted into a format that can be displayed and output by the format control unit 104. Thereafter, the image is processed by the image processing control unit 102 and displayed on the image display unit 103.

  The area designating unit 107 creates a designated area for the input image by image information corresponding to the image input from the image input unit 101 and an area designating operation by the operation unit 108.

  In this embodiment, the luminance signal of the input image is displayed as a waveform. In the present embodiment, the waveform display represents the horizontal coordinate of the input image as the horizontal axis, the luminance signal level of the input image signal as the vertical axis, and the frequency of overlapping data as the luminance of the waveform. As memory for temporarily storing the created waveform data, a total of two built-in memories for waveform creation and waveform readout are used. These two built-in memories are called memory bank 0 and memory bank 1, respectively. One waveform data is created for one frame at the time of image display, and the memory bank 0 and the bank 1 for waveform creation and waveform readout are alternately switched and used for each frame.

  In the present embodiment, the image processing control unit 102 having a flag generation function generates a specified area flag for determining the specified area corresponding to the waveform data to be created from the specified area information, and is built separately from the waveform data. Save to memory.

  In the present embodiment, a case will be described in which waveform data is displayed by changing colors between a predetermined designated area and outside the designated area. Color table A (green) shown in FIG. 5 is referred to outside the designated area, and color table B (red) is referred to the designated area.

  The image processing control unit 102 will be described in detail. FIG. 2 shows the configuration of the image processing control unit 102. The image processing control unit 102 includes a waveform generation unit 201, a waveform color control unit 202, a superimposition processing unit 203, and a memory control unit 204.

  Waveform data is generated by the waveform generation unit 201 from the luminance signal of the image input from the image input unit 101 or the format control unit 104, and is stored in the memory bank 0 by the memory control unit 204. Specifically, the waveform generator 201 considers the current coordinate information of the input image and the signal level for waveform display as orthogonal coordinates, and generates an address for memory access. In the present embodiment, access control to a memory considered as a two-dimensional array is performed with the horizontal coordinate of the input image as the horizontal axis and the amplitude of the luminance signal level of the input image as the vertical axis. In this access, first, the data at the corresponding address is read, and the waveform generation unit 201 multiplies the read data by an arbitrary gain to add the read data, and then writes the same address through the memory control unit 204 again. Processing to return. As a result, it is possible to control the data value at a high frequency so as to increase, and after the processing of one frame at the time of image display is completed, when the read luminance is displayed on the image display unit 103, the high luminance The signal level is bright and the infrequent part appears dark.

  At this time, based on the information indicating whether or not the area is the designated area from the area designating unit 107, the designated area flag corresponding to the waveform data is stored in the memory bank 0 (205) of the built-in memory 204 in association with the waveform data.

  When the generation of the waveform data corresponding to the image signal for one frame is completed, the generated waveform data is stored in the memory bank 1 (206) by the memory control unit 204 from the timing of the next frame. The stored waveform data is read from the memory bank that is not currently accessed by the waveform generation unit 201, and the read value is used as the luminance signal. The corresponding color difference signal is converted into green waveform data by referring to the color table A (Cb = 0x36, Cr = 0x3a), which is a combination of color differences preset at the time of waveform display by the waveform color control unit 202. At this time, the designated area flag corresponding to the waveform data is also read from the built-in memory at the same time, and if it is the designated area data, refer to the color table B dedicated to the designated area (Cb = 0x5a, Cr = 0xf0) Use waveform data. Thereafter, the superimposition processing unit 203 performs superimposition processing of the image data to be displayed on the image display unit 103 and the waveform data, and displays them on the image display unit 103.

  In the present embodiment, it is assumed that face area information corresponding to an image input from the image input unit 101 is an image designation area.

  The display image of this embodiment is shown in FIG. Reference numeral 301 denotes input image data, and reference numeral 3011 denotes a designated area. Reference numeral 302 denotes waveform data of the luminance signal of the input image data. The horizontal axis corresponds to the horizontal pixels of the image data 301, and the vertical axis indicates the distribution of luminance levels of the image data. Reference numeral 303 denotes waveform data existing within the designated area, and reference numeral 304 denotes waveform data existing outside the designated area. Reference numeral 305 denotes a color table that is changed only for the waveform data in the designated area. At this time, when the waveform data existing in the designated area overlaps with the waveform data existing outside the designated area, the data in the designated area is prioritized, and the red color waveform data is obtained with reference to the designated area dedicated color table B. The waveform data is superimposed on the input image data, and the waveform data is displayed in combination with the horizontal pixels of the image 306, and the image data 307 is displayed at the lower right. In both 306 and 307, the correspondence between the position of the image and the position of the designated area in the entire waveform data is matched.

  In this embodiment, the case where there is one designated area has been described. However, when there are a plurality of designated areas, a plurality of color tables are prepared and different colors are used for each area even if all the same color tables are referred to. You may make it refer to a table.

  In the present embodiment, the waveform data is created from the luminance signal of the image signal, but the present invention is not limited to this, and a color difference signal and various RGB signals may be used.

  In addition, as a waveform display, the horizontal pixel of the input image signal is represented by the horizontal axis, and the signal level of the input image signal is represented by the vertical axis, but the vertical line of the input image signal is represented by the vertical axis and the signal level of the input image signal is represented by the horizontal axis. May be represented. Further, although the face area is used as the image designation area, focus area information or area designation information of the image data by the operation unit 108 may be used.

  As described above in the first embodiment, the signal level is displayed as a waveform, and the waveform display method for the signal level included in the image area of interest and the other areas is changed, so that the position with the image can be handled. In this way, the signal level of the attention area can be easily confirmed.

(Second Embodiment)
In the first embodiment, the method of changing the display color of the waveform of the signal level included in the designated area and other areas at the time of waveform display has been described. However, in the second embodiment, the brightness at the time of display is displayed. A method of changing the height (gain) will be described.

  The configuration of the apparatus in the second embodiment is assumed to be the same as that of the first embodiment. The image processing control unit 102 in this embodiment will be described in detail. FIG. 4 shows the configuration of the image processing control unit 102. The image processing control unit 102 includes a waveform generation unit 201, a waveform color control unit 202, a waveform gain control unit 401, a superimposition processing unit 203, and a memory control unit 204.

  In this embodiment, as in the first embodiment, the luminance signal level of the input image signal is displayed in a waveform, and the color table referred to in the waveform color control unit 202 is the color table A (green) shown in FIG. 1 color. Further, when the face area information corresponding to the image input from the image input unit 101 is the designated area of the image, and the signal level outside the designated area is displayed as a waveform, the signal level in the designated area is waveformd. Make the gain (brightness) lower than when displaying. In this embodiment, the waveform outside the designated area is displayed with a half gain.

  A waveform generation unit 201 generates a waveform from a luminance signal of an image signal input from the image input unit 101 or the format control unit 104. At this time, it is stored in the memory bank 0 of the built-in memory 204 until the generation of the waveform for one frame to be displayed on the image display unit is completed. At this time, based on the information indicating whether or not the region is the designated region from the region designating unit 107, the designated region flag corresponding to the waveform data is stored in the memory bank 0 of the built-in memory 204 in association with the waveform data. When the generation of the waveform data corresponding to the image signal for one frame is completed, the generated waveform data is stored in the memory bank 1 of the built-in memory 204 from the timing of the next frame.

  The stored waveform data is read from the memory bank of the built-in memory 204 that is not currently accessed by the waveform generation unit 201, and is a combination of color differences set in advance when the waveform color control unit 202 displays the waveform. Refer to color table A. At this time, the designated area flag corresponding to the waveform data is also read from the built-in memory at the same time, matched with the waveform data referring to the color table, and input to the waveform gain control unit 401. If the designated area flag indicates that the data is outside the designated area, the waveform gain control unit 401 outputs the waveform data by halving the gain. If it indicates that the data is in the specified area, it is output as it is. Thereafter, the superimposition processing unit 203 performs superimposition processing of the image data to be displayed on the image display unit 103 and the waveform data, and displays them on the image display unit 103.

  In the present embodiment, the waveform data is created from the luminance signal of the image signal, but the present invention is not limited to this. In addition, although the face area is used as the image designation area, focus area information or area designation information of the image data designated by the user through the operation unit 108 may be used.

  In this embodiment, gain processing is performed on waveform data outside the specified area. However, waveform data outside the specified area is not subjected to gain processing, and gain processing is performed so that the waveform data gain in the specified area is high. Also good. In that case, according to the size of the designated area, the gain may be changed so as to increase as the size increases.

Claims (19)

An image input means for inputting an image signal;
Waveform generating means for generating a waveform representing a relationship between a position and a signal level in a predetermined direction of the input image signal;
Area designating means for designating a predetermined area of the image signal;
Display means for displaying the image signal and the waveform on a display device;
Control means for controlling the display means so as to change the display method of the waveform of the signal level included in the area designated by the area designation means and the other areas; and
An image display device comprising:   The control means controls the display means so as to display the waveform of the signal level included in the area designated by the area designation means and the other area by changing the display color. Item 4. The image display device according to Item 1.   The control means controls the display means so as to display the waveform of the signal level included in the area designated by the area designation means and the other area by changing the brightness level to be displayed. The image display device according to claim 1, wherein   The control means displays the brightness level for displaying the waveform of the signal level of the area specified by the area specifying means, and the brightness level for displaying the waveform of the signal level of the area not specified by the area specifying means. The image display apparatus according to claim 3, wherein the display unit is controlled to display the image at a higher position.   The control means displays a brightness level for displaying the waveform of the signal level in the area not designated by the area designating means, and a brightness level for displaying the waveform of the signal level in the area designated by the area designating means. The image display apparatus according to claim 3, wherein the display unit is controlled to display the image at a lower level.   The control means controls the display means to change the brightness level for displaying the waveform of the signal level of the designated area according to the size of the area designated by the area designation means. The image display apparatus according to claim 1.   The control means increases the brightness level for displaying the waveform of the signal level included in the designated area and decreases the designated area as the area designated by the area designation means increases. The image display apparatus according to claim 6, wherein the display unit is controlled to lower a brightness level for displaying a waveform of a signal level in the designated area.   The image display apparatus according to claim 1, wherein the area designating unit designates the predetermined area based on image information corresponding to an image signal.   9. The image display apparatus according to claim 8, wherein the image information is any one of face area information, focus area information, and area designation information in an image signal by a user.   The flag generating means for discriminating whether a certain area in the inputted image signal is an area designated by the area designating means or an area not designated. 2. The image display device according to 1. 11. The waveform generation unit according to claim 1, wherein the waveform generation unit counts the signal component at each position in the predetermined direction for each level of the signal level, and generates the waveform corresponding to the count. The image display device according to item 1. The image display apparatus according to claim 11, wherein the waveform generation unit generates the waveform such that an index with a higher count is displayed with higher luminance. The waveform generation means includes memory control means for performing memory access control,
When the image signal from the image sensor is input, the memory control means reads data stored in an address corresponding to the position of the image signal in the predetermined direction and the magnitude of the signal level in the memory, Write back the data plus a specified value to the same address,
The image display device according to claim 1, wherein the waveform generation unit generates the waveform based on an address of the memory and data stored in the address. 14. The display device according to claim 1, wherein the display unit superimposes and displays an image captured by the image sensor and the waveform such that positions in the predetermined direction coincide with each other. Image display device. The image display device according to claim 1, further comprising an operation unit for a photographer to designate the predetermined area. The image input means is an image pickup means for picking up an image and outputting an image signal;
The image display device according to claim 1, wherein the display unit sequentially displays an image signal and the waveform output from the imaging unit. An image input step for inputting an image signal;
A waveform generation step for generating a waveform representing a relationship between a position and a signal level in a predetermined direction of the input image signal;
An area designating step for designating a predetermined area of the image signal;
A display step of displaying the image signal and the waveform on a display device;
A control step of controlling to change the display method of the waveform of the signal level included in the region specified in the region specifying step and the other region, and
An image display method comprising: Imaging means for capturing an image and outputting an image signal;
Waveform generating means for generating a waveform representing a relationship between a position of the image signal in a predetermined direction and a signal level;
Area designating means for designating a predetermined area of the image signal;
Display means for sequentially displaying the image signal and the waveform on a display device;
Control means for controlling the display means so as to change the display method of the waveform of the signal level included in the area designated by the area designation means and the other areas; and
An imaging apparatus comprising: An imaging step of capturing an image and outputting an image signal;
A waveform generation step for generating a waveform representing a relationship between a position in a predetermined direction of the image signal and a signal level;
An area designating step for designating a predetermined area of the image signal;
A display step of sequentially displaying the image signal and the waveform on a display device;
A control step of controlling to change the display method of the waveform of the signal level included in the region specified in the region specifying step and the other region, and
An image pickup apparatus control method comprising: