System for displaying color gamut excursions - Patents.com

Abstract

The test and measurement device includes a graphical display that can serve as an adjunct to the CIE chromaticity diagram 100 when analyzing color images. The graphical display shows an indication of the excursion of pixel colors outside the boundaries of a selected color gamut. The graphical display can show an indication of the excursion relative to one or more reference points.

Description

[Technical field]

[0001] Field of Disclosure FIELD OF THE DISCLOSURE This disclosure relates to test and measurement devices, and more particularly to a system for measuring images and videos and reporting measurements. [Background technology]

[0002] background The well-known CIE 1931 chromaticity diagram, as shown by reference number 100 in FIG. 1, provides a straightforward way to visualize colors in two dimensions. The CIE 1931 chromaticity diagram was developed by the International Commission on Illumination in 1931 based on the observation of colors by a typical observer. The two dimensions of the CIE chromaticity diagram 100 correspond to x and y chromaticity values ​​from the xyY color space, where x and y represent chromaticity and Y represents luminance. It is well known that the xyY color space is derived from the XYZ color space by normalizing the X, Y, and Z components to their sum. In the CIE chromaticity diagram 100, the xy values ​​from the three-dimensional color space of xyY are projected onto a two-dimensional plane along the Y axis. Some versions of the CIE 1931 chromaticity diagram include interior colors, while other chromaticity diagrams, such as the CIE chromaticity diagram 100 in FIG. 1, show only the contours of the color gamut as seen by a typical observer.

[0003] Although the CIE chromaticity diagram 100 in Figure 1 represents colors as seen by the eye of a standard observer, image generating devices such as televisions, tablets, phones, computer monitors, and other types of displays do not typically display such a large gamut of colors. In fact, many color display and reproduction systems can only represent a small subset of the full chroma values ​​shown on the CIE chromaticity diagram 100 in Figure 1.

[0004] FIG. 1 also shows the boundaries of three color gamuts, in this case ITU BT.709 (a standard developed by the International Telecommunication Union Radiocommunication Sector, referenced 110), DCI-P3 (a red-green-blue (RGB) color space developed by the Digital Cinema Initiative, referenced 120), and ITU BT.2020 (another standard developed by the International Telecommunication Union Radiocommunication Sector, referenced 130), superimposed over the 1931 chromaticity diagram 100. Defined color gamuts, such as gamuts 110, 120, and 130 shown in FIG. 1, indicate the outer boundaries of colors that are generated in a particular color gamut. Colors that are inside the CIE chromaticity diagram but outside a particular color gamut are colors that are not supported in the particular color gamut. Note that the color gamut for ITU BT.2020 (130) is larger than the other two gamuts (120, 110). This means that a device conforming to the ITU BT.2020 color gamut 130 can faithfully reproduce more colors than the other color gamuts shown. Conversely, the color gamut ITU BT.709 (110) is the smallest of the three color gamuts shown and cannot faithfully reproduce as many colors as the other two color gamuts shown (120, 130). A television or other display may meet the conditions regarding its ability to adequately display the defined color gamut.

[0005] A case where the CIE chromaticity diagram 100 can be used successfully is in color grading during film / television editing. For example, a colorist may look at the distribution of colors for a scene on the CIE chromaticity diagram and determine whether all colors are within an expected gamut (e.g., ITU BT.709) or whether the colors are in the expected chromaticity positions. The "raw" content used by the colorist typically contains a wide gamut of colors, for example up to the border of the ITU BT.2020 gamut 130. The colorist's job may be to filter the content so that the colors are remapped into the DCI-P3 gamut 120, for example for a cinematic display.

[0006] One of the most common problems with using the CIE chromaticity diagram 100 and gamut boundaries is determining how far a color is from the gamut boundary of interest. If a color is close to a gamut boundary, a colorist may choose to allow the color to be clipped to the gamut edge color rather than risking a hue shift due to color mapping. As shown in FIG. 1, the small area between the gamut triangles makes it difficult for a colorist to accurately evaluate whether and how far the color of a particular pixel that makes up the image may be outside a particular gamut boundary. For example, FIG. 2A is an example base image 200 (originally in color), and FIG. 2B is a chart showing the color locations of the original color pixels that make up the original FIG. 2A plotted on the CIE chromaticity diagram 100 and color gamuts 110, 120, and 130 shown in FIG. 1. It should be noted that plotting a frame of video on the CIE chromaticity diagram 100 is achieved by mapping only the colors represented by each pixel in the frame onto the chromaticity diagram, not the locations of the pixels that make up the frame. Each pixel that constitutes the basic image 200 has a specific color, which is represented as a single location on the CIE chromaticity diagram 100 or other chromaticity diagram. Mapping all of the colors of the pixels that constitute the frame produces a set of color dots or pixels on the chromaticity diagram. Since the CIE chromaticity diagram 100 contains all of the colors that are commonly visible to humans, all of the colors of the pixels of any frame of a video can be mapped to the CIE chromaticity diagram 100. However, a color gamut, which is a predefined set of colors, does not cover the entire CIE chromaticity diagram 100, as shown in FIG. 2B, so even if all of the colors of the pixels that constitute the frame are represented somewhere on the CIE chromaticity diagram 100, some of the colors that constitute the image may be inside or outside a particular color gamut.

[0007] Note how difficult it is to determine whether any of the individual pixels lie inside or outside a particular color gamut, as there is a wide distribution of colors outside the BT.709 gamut boundary 110. As can be seen from the CIE chromaticity diagram 100 in Figure 2B, it becomes difficult to estimate the amount of excursion outside the BT.709 gamut boundary 110, especially for colors closer to blue or red.

[0008] In addition, the non-linear nature of overlapping gamut boundaries makes it difficult and counter-intuitive for colorists to globally view color excursions outside of a particular gamut boundary.

[0009] Embodiments of the present disclosure seek to address these and other limitations in the prior art. [Brief description of the drawings]

[0010] BRIEF DESCRIPTION OF THE DRAWINGS [Figure 1] FIG. 1 illustrates a CIE 1931 standard observer chromaticity diagram with three color gamuts superimposed thereon that may be used in accordance with embodiments of the present disclosure.

[0011] [Figure 2A] FIG. 2A is the image that is analyzed.

[0012] [Figure 2B] FIG. 2B is a color chart for the image of FIG. 2A.

[0013] [Figure 3A] FIG. 3A is a diagram illustrating an example color gamut excursion according to an embodiment of the present invention.

[0014] [Figure 3B] FIG. 3B is a graph illustrating a new method of conveying color gamut excursions.

[0015] [Figure 4]FIG. 4 is a flow diagram illustrating example operations for generating a gamut excursion graph according to an embodiment of the present disclosure.

[0016] [Diagram 5] FIG. 5 is a rendering of an example display screen of a measurement device including a gamut excursion graph according to an embodiment of the present disclosure.

[0017] [Figure 6] FIG. 6 is a functional block diagram of a test and measurement instrument, such as a video analysis waveform tool, that includes a system for displaying color gamut excursions according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] explanation FIG. 3A is a diagram 300 showing an example color gamut excursion according to an embodiment of the present disclosure. Similar to the diagram of FIG. 1, the diagram 300 of FIG. 3A shows the contours of the CIE 1931 chromaticity diagram 100 as well as the contours for the ITU BT.709 (110), DCI-P3 (120), and ITU BT.2020 gamuts (130). In addition, a white point 350 is shown near the center of the CIE 1931 chromaticity diagram 100. FIG. 3B is a graph 380 showing a new representation for visually conveying color gamut excursion to a user according to an embodiment of the present disclosure, which will be described in detail below. In practice, the graph 380 can be generated on a display of a video analyzer or other video measurement device.

[0019] For purposes of illustration, assume that point P1 in FIG. 3A represents the color of a pixel of interest in an image. Note that P1 is outside the BT.709 gamut 110, but is inside the BT.2020 gamut 130 and the DCI-P3 gamut 120. Generally, the embodiments disclosed herein generate a separate indication, other than in the CIE chromaticity diagram, of whether the color of interest is outside the gamut of interest. Furthermore, if the color is in fact outside the gamut of interest, the embodiments of the present invention use the graph 380 in FIG. 3B to communicate what color the pixel is and how much it is outside the gamut. The user can then use the graph 380 in FIG. 3B to help visualize and determine the degree of color violation of the gamut.

[0020] Graph 380 of Figure 3B contains a number of elements. First, the graph's background 382 maps 0 to 359 degrees on its X-axis to the percentage of excursion on its Y-axis. Color bar 384 (colored in the original) shows a spectrum of colors from the CIE 1931 chromaticity diagram 100. The primary colors represented in color bar 384 range from left to right: orange, yellow, green, light blue, dark blue, crimson, and red. As can be seen in Figure 3B, color bar 384 is a continuous spectrum of colors.

[0021] A user can use the graph 380 of Figure 3B in a number of ways. For example, if the color of interest is slightly outside the gamut of interest, the colorist can choose the color to be clipped in the gamut, i.e., represented as well as possible, by a color at the edge of a particular gamut, even though it is not the actual absolute color of the original pixel. Using embodiments of the present invention, this determination can be made quickly and easily, and much easier than searching for a small pixel on a crowded gamut diagram.

[0022] Returning to Figure 3A, an embodiment of the present disclosure generates a line segment that extends from the white point 350 on the CIE chromaticity diagram 100, through the pixel of interest P1, to the edge of the outermost gamut in the analysis. In this example, the outermost gamut is BT.2020130, with point A1 indicating the end of this line segment at the edge of gamut 130. This line segment also includes point B1, which is a point on the generated line segment that is at the edge of the BT.709 gamut 110, which is the gamut of interest for this example and is the gamut shown in Figure 3B.

[0023] Also, the rotation angle / radiation angle of the generated line segment (i.e., the line segment from the white point 350 to A1) can be measured from the relative starting point or starting line. In the example shown in FIG. 3A, the starting line (0 degrees) is a line that runs exactly horizontally from the white point 350 along the CIE 1931 chromaticity diagram 100. In other embodiments, the starting line can be a virtual line 352 that passes through the white point 350 and the red primary of the BT.709 gamut 110, a virtual line 354 that passes through the white point 350 and the red primary of the DCI-P3 gamut 120, or a virtual line 356 that passes through the white point 350 and the red primary of the BT.2020 gamut 130. It should be noted that the starting lines 352, 354, 356 that pass from the white point 350 and the red primary of the respective gamuts 110, 120, 130 are slightly different from the starting line that runs horizontally through the white point 350. This small offset is due to the red primaries of each gamut 110, 120, 130 being at slightly different locations on the CIE 1931 chromaticity diagram 100. Of course, the orientation of the radial reference lines is arbitrary, and the relative rotation of the generated lines may be measured from any desired starting or reference line. For the illustrated example, the gamut of interest is the BT.709 gamut 110. By providing the user with the relative rotation distance from the baseline, in addition to providing the line length from the starting point to the pixel of interest, a mechanism is provided for the user to uniquely identify the pixel of interest. Also, although the present embodiment uses line length and rotation to determine the location of a pixel outside the gamut of interest, other pixel location identifiers could be used, such as a grid system based on a Cartesian plane or other location system. It should be noted that with reference to the CIE chromaticity diagram 100, the term "pixel location" or other similar terms refers to the location of a particular color within the chromaticity diagram 100, and not the location of the pixel within the original frame of the video that is mapped to the chromaticity diagram as described above.

[0024] In the distance+rotation embodiment described herein, the measurement of the length of the line segment from the white point 350 to A1 can be done in a number of ways. One such measurement method is to create a range starting from the edge of the color gamut of interest and ending at the largest color gamut represented on the graph. In the example shown in FIG. 3A, point B1 is the 0% reference point (i.e., if a color point were located there, it would be 0% outside the color gamut of interest), and point A1 is the 100% reference point. In other words, in this measurement method, the position of the point of interest P1 is measured on a relative scale between 0% and 100%, which reflects the relative distance of point P1 between the color gamut of interest and the color gamut that is the outermost in the CIE 1931 chromaticity diagram 100.

[0025] After generating a line segment through point P1 and determining the relative distance of P1 on the line segment, and after determining the rotation angle of the line segment, this information can be mapped onto a graph 380 (FIG. 3B) and presented to the user. In this example, for ease of illustration, only a single pixel located at P1 in the diagram shown in FIG. 3A is shown in the graph of FIG. 3B as a bar 386. A representation of this pixel is shown in 3B by bar 386, located at approximately 120 degrees measured from the reference line, and the bar graph indicates that the pixel is approximately 20% outside the gamut of interest. Thus, graph 380 of FIG. 3B conveys important information about how far the pixel's color is outside the gamut, i.e., the excursion distance, along with the color of the pixel itself.

[0026] Note that in this example, FIG. 3B shows pixel color excursions outside the BT.709 gamut 110. If instead the DCI-P3 gamut 120 or the BT.2020 gamut 130 were analyzed, the graph 380 would not have pixels outside the respective gamuts and the graph 380 would remain blank for the particular frame being analyzed. In practice, the graph 380 could be generated for any selected image frame and for any selected color gamut, with the operator having a mechanism to manually or automatically go through individual frames of interest in the video looking for gamut color deviations. These appear as bars of varying height along the Y axis and position along the X axis showing all of the gamut color deviations for the particular frame being analyzed. The user also has a mechanism to select for which color gamut 110, 120, 130 or other color gamut the graph 380 is generated.

[0027] A user may set predefined thresholds to facilitate the analysis. In FIG. 3B, two such thresholds, threshold A and threshold B, are shown on graph 380 to increase the ease with which graph 380 conveys information of pixel color excursions outside a particular color gamut. Various actions may be taken when a bar 386 exceeds a threshold. For example, when a bar that exceeds threshold A appears on graph 380, the color of bar 386 may change to yellow, etc., and when a bar that exceeds threshold B appears on graph 380, the color of bar 386 may change to red. Alternatively or additionally, the threshold exceedance may be recorded in a list together with the frame number, position angle, and percentage of gamut excursion for each gamut deviation, which may be reviewed later. The number of thresholds that may be generated is variable, and individual thresholds may be set for each color gamut to be analyzed. In other words, the threshold levels may not be the same for all color gamuts.

[0028] FIG. 4 is a flow diagram illustrating example operations of a flow 400 for generating a gamut excursion graph according to an embodiment of the present invention. The flow begins with operation 402 when a video frame is received for processing. The flow 400 receives some information. This information may be received from a user or may be preset. For example, the flow 400 receives a gamma selection 404, a gamut selection 408, and a target gamut 416. The flow 400 then proceeds to operation 406, removes gamma 410, converts the color space to an XYZ color space 412, and converts the color space from XYZ to xyY. The x and y coordinates from operation 412 may be expressed as (x,y) and may be referred to as the chromaticity coordinates of the particular pixel being analyzed. Operations 402-412 are conventional and will not be discussed further. In one embodiment, operations 402-412 are repeated for all of the pixels in a particular frame, or even for all of the pixels in a particular portion of a video consisting of multiple frames, before being analyzed for gamut excursions in operations 414-428.

[0029] Operation 414 compares the (x,y) chromaticity coordinates of the current pixel to determine whether it is inside or outside a target gamut, such as BT.709. If the (x,y) chromaticity coordinates of the current pixel lie inside the target gamut, i.e., inside the gamut triangle, the pixel is ignored on the graph and operation 418 gets the next pixel to be processed.

[0030] On the other hand, if the (x,y) chromaticity coordinates of the current pixel are outside the target gamut, such as P1 for BT.709 (110) in FIG. 3A, flow 400 continues with the operations of creating an excursion graph as described above with reference to FIGS. 3A and 3B.

[0031] First, in operation 420, an extension line is generated from the white point 350 through the (x,y) chromaticity coordinates of the current pixel. In one embodiment, the ends of this line are the boundaries of the outermost or widest gamut where the white point 350 and the gamut of interest are measured. In other embodiments, the line length may be created or referenced differently to other gamuts, or even to the edges of the CIE 1931 chromaticity diagram itself. Referring back to FIG. 3A, the line extends from the white point 350 to A1.

[0032] Next, the intersection points of the generated line with a) the edge of the gamut of interest and b) the edge of the reference gamut are determined. Referring back to Figure 3A, these are points B1 and A1, which are the intersection points of the generated line with the BT.709 gamut 110 and the BT.2020 gamut 130.

[0033] Then, in operation 422, the relative distance of point P1 between points B1 and A1 is determined. In other words, how far does point P1 extend between points B1 and A1? In the example taken with reference to FIG. 3A, point P1 extends about 20% of the distance between B1 and A1. The relative distance may be expressed as a percentage as shown in operation 424. As described below, the relative distance of the excursion of P1 outside the gamut of interest may be calculated in other ways using other line lengths in the percentage calculation. Other relative distance measurements may be used, such as, for example, reference to a linear or non-linear scale. Thus, the particular reference used to measure the excursion may be specific to the method implemented.

[0034] At the same time, in operation 426, the hue angle of the generated line may be determined. Recall from above that the reference line may be generated, for example, from the line 352, 354, or 356 passing from the white point 350 through the red primary vertex of the gamut of interest. Alternatively, the reference line may be a horizontal line extending from the white point 350, whatever gamut is being used as the gamut of interest. Also, as mentioned above, the hue angle of the generated line may be formed from the desired line as a radial reference line.

[0035] Finally, after the hue angle has been determined in operation 426, the information generated in operations 420-426 is graphed in operation 428 for the pixel of interest to generate a representation of the pixel of interest on a graph, such as graph 380 shown in FIG. 3B, which is presented to the user.

[0036] Note that in some embodiments, operations 420-428 are repeated for each pixel in the selected image that is outside the selected gamut of interest and is mapped onto a single graph 380. Thus, unlike the example of FIG. 3B, a graph generated for all of the gamut excursions in the video frames will likely contain many data points, perhaps on the order of hundreds or thousands. The graph may specify the number of frames for a particular excursion. In other embodiments, individual graphs such as 380 may be generated for each frame in the selected portion of the video. The user may then proceed to look for gamut deviations through the individual graphs 380. In yet other embodiments, only the specific graphs 380 may be generated for frames that exceed pre-defined thresholds, not just threshold A and threshold B, but also for gamut deviations above 0%.

[0037] Overall, the graph generated as described above helps the user quickly identify various colors that have excursions outside the target gamut boundary.

[0038] FIG. 5 is an image 500 of a display (also called a display) of a test and measurement device that can be used to generate and show the excursion graphs described above to a user. The image to be analyzed is located in the upper left corner of FIG. 5. A representation of the colors 512 of the test image 510 can also be presented on the display. A state of the art CIE and gamut graph 520 is shown in the top center of the screenshot. The upper right part of the display provides a user interface 530 that allows the user to select the desired gamut, pixel persistence, luma test, etc. to help define what the user sees on the display 540 (which can be an embodiment of the graph 380 of FIG. 3B). Along the bottom of the image is an example of a graph in the display 540 generated as described above with reference to FIG. 3B. The spike seen on the display 540 near 105 degrees indicates that there are green pixels in the test image that are outside the selected BT.709 gamut. There are other spikes around 150 degrees and a single spike near 180 degrees. These spikes on the graph in display 540 alert the user to other color excursions that fall outside the selected color gamut. Threshold A, threshold B, and other items may be set through the user interface 530 or by adding them to display 540 and dragging them to the desired location. Additionally, a color bar 542 may be presented below the graph in display 540 to allow the user to quickly see where the colors of the image or video being processed fall outside the selected color gamut. Additionally, the graph bar itself may be presented with the actual colors that are outside the range of the color gamut. Furthermore, in some embodiments, pixels in the test image 510 may be modified during processing to generate a false color or heat map with varying intensities related to pixels of the image that contain colors outside the selected color gamut. Pixels of the test image 510 that have colors that lie entirely within the selected color gamut are not modified. Thus, when a user views a test image 510 with a lot of false colors, the user can easily see where gamut excursions are occurring on the test image 510.5 shows the various portions on a black background, the background and graphs of any of these portions may be other colors, such as white, and not all of the elements of image 500 must be present in all embodiments of the invention.

[0039] The concept of the gamut excursion graph described above can be applied to any source and destination gamut boundary, including gamuts not currently defined. Also, different representations of the reference length (denominator in the length ratio) may be used to measure the excursion in percentage. For example, the graph shown in FIG. 5 uses the ratio of the distance between points P1 and B1 to the distance between white point 350 and B1 (FIG. 3A). Therefore, in cases such as those shown in FIG. 5, the graph height may exceed 100%. In other embodiments, the excursion distance may use a non-linear scale. In still other embodiments, the excursion distance in either a linear or non-linear scale may fall into definable excursion zones, so that a level 5 excursion may be a more severe gamut violation than a level 2 violation. As above, any criteria for angle or distance may be selected without departing from the scope of the invention, or other mechanisms for identifying pixels outside the selected gamut may be used.

[0040] In some embodiments, the display 500 can be constructed using the 1976 CIE chromaticity diagram rather than the 1931 CIE chromaticity diagram 100 illustrated herein. The 1976 CIE chromaticity diagram has the added advantage that the distance between points on the chart is perceptually linear; that is, with the 1976 CIE chromaticity diagram, equal distances between points indicate equal changes in chromaticity, unlike the 1931 CIE chromaticity diagram 100. Of course, other chromaticity diagrams can be used in other embodiments.

[0041] 6 is a functional block diagram of a test and measurement system 600 including test and measurement equipment, such as a video analysis waveform tool, that includes a system for displaying color gamut excursions according to an embodiment of the present disclosure. The test and measurement system 600 includes a source 610 for video to be analyzed as well as equipment 620 for analyzing video, such as a video waveform monitor. The source 610 for video may transmit the video via conventional means to equipment 620 for analysis, such as via a direct video connection or using Internet Protocol (IP).

[0042] Device 620 includes a video input 622 for accepting video from source 610, as well as a video processor 624 capable of operating embodiments of the present invention. In practice, there may be multiple video inputs 622 in device 620 to accept multiple different video streams from multiple sources 610.

[0043] The one or more processors 626 may be separate from the video processor 624, or in some embodiments, the processing functions for operating the device 620 and performing the video analysis may be included within a single processor. In other embodiments, the processing functions for operating the device 620 and performing the video analysis may be distributed across multiple processors, as known in the art. The one or more processors 626 may be configured to execute instructions from the memory 627 and may perform the method and / or related steps indicated by such instructions, such as receiving, analyzing, measuring, storing, and displaying the results of such operations on the display 630. The display 630 may be the same as or similar to the display 500 described with reference to FIG. 5. The memory 627 may be implemented as a processor cache, random access memory (RAM), read-only memory (ROM), solid-state memory, a hard disk drive, or other memory type. The memory 627 may also function as a medium for storing video data, computer program products, and other instructions, as known in the art. Video processor 624 may include its own memory for similar functions or may be coupled to or operate from memory 627 .

[0044] User input 628 is coupled to processor 116. User input 628 may include a keyboard, mouse, touch screen, and / or other controls available to a user to configure and control device 620. User input 628 may also include a graphical user interface on display 630, or may be embodied entirely by display 630. User input 628 may further include program inputs from a user on device 620 or from a remote device.

[0045] Although the components of the test instrument 620 are shown as integrated within the test and measurement instrument, it will be understood by one of ordinary skill in the art that any of these components may be external to the test instrument 620 and coupled to the test instrument in any conventional manner (e.g., wired and / or wireless communication mediums and / or mechanisms). For example, in some embodiments, the display 630 may be remote from the test and measurement instrument 620, or the instrument may be configured to transmit its output to a remote device in addition to displaying the output on the instrument 620. In further embodiments, the output from the measurement instrument 620 may be transmitted to or stored within a remote device, such as a cloud device accessible from other machines coupled to the cloud device.

[0046] Working Example Illustrative examples of the techniques disclosed herein are provided below. Configurations of the present techniques may include one or more, and any combination, of the examples described below.

[0047] Example 1 is a display for displaying information from a video frame for a selected color gamut including a defined set of colors, the display having an indication of pixel positions for pixel colors in the video frame that exceed a range of colors within the selected color gamut, the indication of the pixel positions including position references referenced from a reference point.

[0048] Example 2 is a display for displaying information from a video frame according to example 1, wherein the reference point is within the selected color gamut.

[0049] Example 3 is a display for displaying information from a video frame according to example 1, wherein said reference point is a white point.

[0050] Example 4 is a display for displaying information from a video frame as described in any of the preceding examples, wherein the display is an element on a graph including an angular position reference and a distance reference to the pixel position from the reference point.

[0051] Example 5 is a display for displaying information from a video frame as recited in example 4, wherein the distance reference is a distance from an outer edge of the selected color gamut to the pixel location.

[0052] Example 6 is a display for displaying information from a video frame as described in Example 5, wherein the distance is a relative distance of the pixel position between the outer edge of the selected color gamut and a second reference point.

[0053] Example 7 is a display for displaying information from video frames according to example 5 or 6, wherein the relative distance is a linear or non-linear representation.

[0054] Example 8 is a display for displaying information from a video frame according to example 6, wherein the second reference point is an edge of a non-selected color gamut.

[0055] Example 9 is a display for displaying information from a video frame according to Example 6, wherein the second reference point is an edge of a chromaticity diagram.

[0056] Example 10 is a display for displaying information from a video frame as described in Example 4, wherein the representation is colored to match the colors of the pixel colors in the video frame that exceed the range of colors within the selected color gamut.

[0057] Example 11 is a display for displaying information from a video frame according to Example 4, further comprising a color bar showing individual colors of the selected color gamut for each angular position reference.

[0058] Example 12 is a display for displaying information from a video frame according to any of the preceding examples, further comprising a visual representation of the video frame in which the colors of individual pixels outside the selected color gamut appear as falsely colored pixels.

[0059] Example 13 is a display for displaying information from a video frame according to Example 12, in which the colours of individual pixels within the selected colour gamut retain their original colours.

[0060] Example 14 is a video waveform monitor comprising an input for receiving video comprising one or more video frames, a video processor for analyzing the one or more frames of the video, and a display for displaying information from the one or more video frames for a selected color gamut comprising a defined set of colors, the display having an indication of pixel positions for pixel colors in the video frames that exceed a range of colors within the selected color gamut, the indication of the pixel positions including position references referenced from a reference point.

[0061] Example 15 is the video waveform monitor of example 14, wherein the representation on the display is a graphical element including an angular position reference and a distance reference to the pixel position from the reference point.

[0062] Example 16 is a method for indicating an amount of gamut excursion of a pixel in a frame of a video having a color that is not within a defined set of colors for a selected color gamut, comprising determining a color of a pixel in the frame, evaluating whether the color of the pixel is within the defined set of colors for the selected color gamut, generating a position graph, and adding an indication on the position graph for only those pixels of the frame that have a color that is within the defined set of colors for the selected color gamut.

[0063] Example 17 is the method of example 16, wherein the display on the position graph includes position references to each pixel of the frame having a color that falls within the defined set of colors for the selected color gamut.

[0064] Example 18 is the method of example 16, wherein the element on the position graph includes an angular position reference and a distance reference from a predefined reference point.

[0065] Example 19 is the method of example 17, wherein the predefined reference point is a color point within the selected color gamut.

[0066] Example 20 is the method of example 17, wherein the distance reference indicates a scaled distance between an edge of the gamut and a second reference point.

[0067] Example 21 is the method of example 19, wherein the second reference point is an edge of the unselected color gamut.

[0068] Furthermore, the description herein refers to specific features, and it is to be understood that the disclosure herein includes all possible combinations of those specific features, for example, if a particular feature is disclosed in the context of a particular embodiment, that feature can also be used to the extent possible in the context of other embodiments.

[0069] Additionally, when this application refers to a method having two or more defined steps or actions, those defined steps or actions can be performed in any order or simultaneously, unless the context excludes such possibility.

[0070] All features disclosed in this specification, including the claims, abstract, and drawings, and all steps in the disclosed methods or processes, may be combined in any combination, except combinations in which at least some of such features and / or steps are mutually exclusive. Each feature disclosed in this specification, including the claims, abstract, and drawings, may be replaced by another feature achieving the same, equivalent, or similar purpose, unless expressly stated otherwise.

[0071] While particular aspects of the present disclosure have been illustrated and described for purposes of illustration, it will be understood that various modifications can be made without departing from the spirit and scope of the disclosure. Accordingly, the present disclosure should not be limited except as by the appended claims.

Claims

1. 1. A display for displaying information from a video frame for a selected color gamut that includes a defined set of colors, comprising: and an indication of pixel locations for pixel colors in the video frame that exceed a range of colors within the selected color gamut, the indication of the pixel locations including location references referenced from a reference point. display.

2. A display for displaying information from a video frame as claimed in claim 1 , wherein the reference point is within the selected colour gamut.

3. A display for displaying information from a video frame as claimed in claim 1 , wherein said reference point is a white point.

4. 2. A display for displaying information from video frames as claimed in claim 1, wherein the representation is a graphical element including an angular position reference and a distance reference to the pixel position from the reference point.

5. A display for displaying information from video frames as claimed in claim 4, wherein the distance reference is the distance from an outer edge of the selected colour gamut to the pixel location.

6. 6. A display for displaying information from video frames as claimed in claim 5, wherein the distance is the relative distance of the pixel location between an outer edge of the selected colour gamut and a second reference point.

7. A display for displaying information from video frames as claimed in claim 6, wherein the relative distance is a linear or non-linear representation.

8. A display for displaying information from a video frame as claimed in claim 6, wherein the second reference point is an edge of a non-selected colour gamut.

9. 7. A display for displaying information from a video frame as claimed in claim 6, wherein said second reference point is an edge of a chromaticity diagram.

10. 5. A display for displaying information from a video frame as claimed in claim 4, wherein the display is coloured to match the colours of the pixels in the video frame that exceed the range of colours within the selected colour gamut.

11. 5. A display for displaying information from video frames as claimed in claim 4, further comprising a colour bar showing individual colours of the selected colour gamut for respective angular position references.

12. 2. A display for displaying information from a video frame as claimed in claim 1, further comprising a visual representation of said video frame in which colours of individual pixels outside said selected colour gamut appear as falsely coloured pixels.

13. A display for displaying information from video frames as claimed in claim 12, wherein the colours of individual pixels within the selected colour gamut retain their original colours.

14. 1. A video waveform monitor comprising: an input for receiving a video comprising one or more video frames; a video processor for analyzing the one or more video frames of the video; a display for displaying information from the one or more video frames for a selected color gamut that includes a defined set of colors, the display having pixel location indications for pixel colors in the video frames that exceed a range of colors within the selected color gamut; Equipped with the representation of the pixel location includes a location referenced from a reference point; Video waveform monitor.

15. 15. A video waveform monitor as claimed in claim 14, wherein the representation on the display is a graphical element including an angular position reference and a distance reference to the pixel position from the reference point.

16. 1. A method for indicating an amount of gamut excursion of a pixel in a frame of video having a color that is not within a set of colors defined for a selected color gamut, comprising: determining a color of a pixel in the frame; Evaluating whether the color of the pixel is within the defined set of colors for the selected color gamut; Generate a position graph, adding indications on said position graph for only those pixels of said frame having colors that fall within said defined set of colors for said selected color gamut; method.

17. The method of claim 16 , wherein the representation on the position graph includes position references to each pixel of the frame having a color that falls within the defined set of colors for the selected color gamut.

18. 20. The method of claim 17, wherein an element on the position graph includes an angular position reference and a distance reference from a predefined reference point.

19. The method of claim 18 , wherein the predefined reference points are color points within the selected color gamut.

20. The method of claim 19 , wherein the distance reference indicates a scaled distance between an edge of the gamut and a second reference point.

21. The method of claim 20, wherein the second reference point is an edge of a non-selected color gamut.

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