Removing digital noise

The term “noise” as it relates to photos refers to small specks of color that interfere with image clarity. These specks are usually caused by poor lighting conditions or the limitations of the sensor in your digital camera. For example, when you zoom in on a photo of a clear blue sky, you may see tiny specks of orange, red, purple, green, or other colors.

Corel PaintShop Pro gives you two fast, powerful commands for removing noise from your photos: One Step Noise Removal and Digital Noise Removal. When you use a noise removal command, the program analyzes your photo, identifies the noise artifacts, and applies corrections based on these identified areas, while preserving the important edge details of your photo.

The image on the left looks grainy because of digital camera noise. The image on the right appears smoother and less grainy after the noise has been removed.

You can automatically apply noise correction to your photo with the One Step Noise Removal command. You can also control more precisely how the same corrections are applied by using the more comprehensive Digital Noise Removal command.

Digital Noise Removal command

The Digital Noise Removal command gives you more control over the removal of digital camera noise in your photos.

Photos taken with the same camera tend to have noise in the same areas. You can create a preset to apply the same corrections to all of these photos.

This command could be an ideal solution in the following scenarios:

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For photos that most likely contain excessive noise (such as a video whiteboard capture), using the command with low settings can help make the overall image clearer without excessive blurring.

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For photos taken with normal settings, this command is best used only on key areas needing correction, such as image artifacts surrounding the subject area.

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For photos containing areas that you want to exclude from the noise correction, you can specify the color ranges to preserve or discard. For example, you may want to protect skin tones in a photo from having any correction applied to them. You can define as many of these protected regions as you like.

To remove digital noise quickly

Edit workspace

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Choose Adjust

One Step Noise Removal.

After a brief pause, the noise is automatically removed.

To use advanced options for removing digital noise

Edit workspace

Choose Adjust

Digital Noise Removal.

The Digital Noise Removal dialog box appears.

The three crosshairs appear on the image preview in the Remove Noise tabbed area. The crosshairs represent noise samples located in the image’s light, midtone, and dark areas. You can move a crosshair by dragging the bounding box in the before pane, which moves the sampling region accordingly.

In the Remove Noise tabbed area, mark the Link detail sizes check box to adjust the Small, Medium, and Large settings in proportion to each other.

Type or set values in the Small, Medium, and Large controls.

These controls define the amount of correction to apply to small, medium, and large noise patterns.

Type or set a value in the Correction blend control to determine to what degree the corrected image will be blended in with the original.

The blending values range from 0.0 (no noise reduction) to 100.0 (full processing of the entire image). The default value is 70.

Type or set a value in the Sharpening control to determine the degree of sharpening, if any, to apply to the image after the noise reduction is applied.

The default value is 0.

Click OK.


You can also
Set corrections for light, midtone, and dark areas independently	Unmark the Link detail sizes check box, and type or set values in the Small, Medium, and Large controls.
View close-ups of sampling regions	Click a crosshair to see the area close up in the Before and After panes.
Add a sampling region crosshair	Drag in the Before pane.
Delete a sampling region crosshair	In the Before pane, drag a corner of the correction box to its diagonally opposite corner.

You can have a maximum of 10 sampling regions.

You should avoid sampling an image edge, or pure black or pure white regions of the image, which can result in excessive smoothing.

The Digital Noise Removal command is not designed to remove moire patterns. For information about removing moire patterns, see To remove moire patterns.

To save settings as a preset specific to an image and camera, mark the Camera preset check box and click the Save Preset button

. When the Camera preset check box is marked, the Load Preset drop-list displays only previously saved camera presets, not the standard presets. To save settings as a standard preset, unmark the Camera preset check box, and click the Save Preset button.

For best results when working with JPEG images, choose Adjust

Add/Remove Noise

JPEG Artifact Removal before using the Adjust

Digital Noise Removal command.

To protect image areas from noise corrections

Edit workspace

Choose Adjust

Digital Noise Removal.

The Digital Noise Removal dialog box appears.

Click the Protect Image tab.

In the Before pane, pan and zoom as necessary so that you can view the region you want to protect.

Hold down Ctrl, and drag over the region you want to protect.

Holding down Ctrl does not create a corresponding crosshair in the image window of the Remove Noise tabbed area.

In the Selected hue range group box, type or set values in the Hue and Range controls.

The existing settings reflect the area sampled. You can manually adjust the hue knob by dragging it inside the ring.

In the Protect selected hue range group box, drag any of the seven graph handles downward to apply less correction and smoothing to the corresponding segment of the hue range.

For example, dragging just the middle graph handle to the bottom of the graph completely suppresses the midtone of that hue range.

The graph handles cannot be dragged laterally.

Click OK.

You can remove color adjustments for a selected color range by clicking Reset Current. To remove all color adjustments, click Reset All.