Using the Histogram

Katana comes equipped with a Histogram tab for checking RGBA levels within an image.

Note:  The Histogram tab works in conjunction with the Pixel probe in the Monitor tab. To view anything within the Histogram tab you must have a point or area selected with the probe.

The image’s channels are plotted with the value along the horizontal axis and the count for that value along the vertical axis. The top histogram matches the Front image and the bottom histogram matches the Back image.

To view the count at a particular value, click anywhere within either histogram. The RGBA channel’s count for that value displays towards the top of each histogram. The format of the display is <value> : <red count> <green count> <blue count> <alpha count> .

To change the colorspace used for plotting values within the histogram, click the colorspace dropdown and select one of the provided options - these options come from the current OpenColorIO profile. For more on OpenColorIO, see Managing Color.

To change the scale of the plotted values in the Y axis, enter a new value within the vScale field.

To toggle a channel's display within the Histogram tab, click the letter that represents the channel at the top-right of the tab.

Tip:  Along the bottom of each histogram a colored dot shows the lowest and highest value for each channel displayed.

Note:  The plotted value does not necessarily correspond to an actual value. For instance, the range for the lnf colorspace within the Histogram tab is 0 to 1023 whereas the actual values are 32-bit floating point. Katana maps the colorspace values to a range for display purposes.