Go to Image-->Histogram on the menu bar. In the channel box, select the red channel. Write down the value for the mean. Repeat for the green and blue channels.
A set of photos taken with the same camera setup may differ due to variability in lighting, equipment, etc. Inclusion of a color card standard in each photo allows the entire image to be adjusted for these differences in lighting. Adjusting the images to a standard improves the ability of the image analysis software to separate colors as desired. The color card comes with a chart listing the red, green, and blue values for the standard colors. The values from the chart can be compared with values for the image from PhotoPaint. The difference in the chart and PhotoPaint values is used to adjust the image. The specific color square chosen for the correction should not be a color from the area of the image that is of interest. The gray squares are usually good choices. Currently, the steps for this procedure are not automated and user intervention is required for each image.
Varies with number of photos to be color corrected
| Step | Image |
| Open image in Corel PhotoPaint. Select an area within the color card square. This example is done using the Neutral 5 square. | |
Go to Image-->Histogram on the menu bar. In the channel box, select the red channel. Write down the value for the mean. Repeat for the green and blue channels. |
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| Enter the red, green, and blue (RGB) values in the color calibration spreadsheet . The correction factors will be calculated automatically. The corrections for all images may be done in one spreadsheet by identifying the image in the pot number column. | |
| Undo the rectangle mask with Mask-->Remove. This will correct the entire image instead of just the selected square. Go to Image-->Adjust-->Color Balance. | |
| Enter the RGB correction factors calculated in the spreadsheet into the white boxes. Click OK when finished. | |
| Create a color corrected images folder using Windows Explorer in the same location as the original files. Go to File-->Export-->Export. Locate the color corrected images folder and save the images in TIF format. Do not save over original images. At this point the images may be cropped if necessary or taken directly into IPLab. | |