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5.1 Capture

This menu groups operations which are useful in capturing images, or for the inital processing you might want to do to an image captured from another program.

Capture_video
This menu item will currently only work on Linux machines with a compatible video4linux capture card. See §3.2.1 for notes on how it works.

Light_correct
Use this to correct homogeneity. Select an image of a piece of white (or mid-grey) card, then select the image to correct, then click Light_correct.

You can select a single white and a group of images to correct a large set in one step

White_balance
Use this to move the white point to make an area of the image you know to be white, white. Mark a region on an image, enclosing a patch you know to be white. Click on White_balance.

Smooth_image
Use this to remove texture from images. It's handy in conjunction with the Light_correct item. Apply this item to an image to make a smoothing widget, open up the row, and move the slider to select the size of feature you want to remove.

Calibrate_chart
Use this to make a colour calibration image. Apply to a cropped RGB image of a Macbeth Color Checker Chart to make a calibrated CIELAB image. sInside the row you'll see metrics on calibration quality, and the calculated transform.

Calibrate_image
Use this to apply the transform calculated by the previous item to another image. Select the calibrated chart image, select the RGB image you want calibrated, and click Calibrate_image.


next up previous contents
Next: 5.2 Colour Up: 5. Image processing menus Previous: 5. Image processing menus   Contents
John Cupitt 2003-07-21