Advanced PDF image editing

The advanced image editing tools give you powerful tools to find the properties of an image and to edit orientation, color, OPI, sampling, and cropping. (For related information see the edit PDF text & images feature overview.)

To select an image and edit its properties:

1. Open the PDF in Nitro PDF Professional.
2. Do either of the following:
• Choose Tools > Select Image.
• Select the Select Image tool.
3. Do either of the following:
• Double-click on the image to edit.
• Choose Tools > Image Tools > Image Properties.

Info. Provides information on the currently selected image, including its size, rotation, resolution, color space, color channels, bits per channel, and image type.

Orientation. Lets you move, scale, rotate, and horizontally or vertically flip the currently selected image.

Color. Lets you convert color spaces. Also, using the drop down list at the top of the dialog gives you tools to adjust the hue, saturation, brightness, and contrast.

OPI. Lets you create, view, or alter the OPI (open prepress interface) information for an image. Upon confirmation, this information will update the appropriate OPI information stored inside the PDF. OPI is used to swap low resolution images with high resolution versions just prior to printing, and is only really relevant when performing high-end printing jobs.

• Overprint & Transparency. Let you to set/reset these states in the OPI dictionary and are only applicable to OPI version 1.3. The intent is for these parameters to be interpreted and executed by compliant OPI servers downstream. Consult your OPI vendor about whether they support changes to these states. For viewing, Nitro PDF Professional does not currently honor changes to these states. Check marks indicate that the background should be transparent, and that it should overprint, respectively. Usually, the setting for Overprint is unchecked, i.e., knocked out.

Sample/Compress. From this panel you can choose how you would like to resample or compress the currently selected image to reduce the amount of data in it. This results in smaller file sizes and better performance.

• Subsampling. When subsampling an image, a pixel is selected in a sample to represent that area at the new resolution.
• Downsampling. Uses a weighted average of pixels in a sample area to determine pixel color and usually yields better results than subsampling. Each downsampling filter produces differing results and, depending on the image, one filter may produce a better appearance than another. ARTS PDF has tested a range of sample color images at different source and destination resolutions and found that "Lanczos 3" produces consistently good results.

Crop. Lets you crop the image you have selected. Enter values in the Left, Right, Top, or Bottom fields to crop that area of the image.

Note: When an image is cropped the data is removed. It cannot be recovered except by an Undo immediately following the cropping action.

To edit the preferences of the image editing tool:

Images preferences are set by choosing Tools > Image Tools > Image Properties.

Note: Depending on your settings in Tools > Image Tools > Images Tools Preferences, double-clicking on a selected image will launch the 'Image Properties', 'Edit Image', 'Audit Images', 'Despeckle', 'Extract Image', or 'Replace Image' dialog.

Related info: Nitro Pro 5 Help

How to delete images from PDF
How to replace images in PDF
How to edit image color space in PDF
How to insert images into PDF
How to extract images from a PDF
How to crop images in PDF

Related info: Nitro Pro Features

Edit PDF

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