Edit Images on Mac: Crop, Resize, Rotate with Preview
Preview: More Than Just a PDF Reader
The Preview application on your Mac is often thought of as a PDF editor. However, it also functions effectively as a surprisingly capable image editor.
It provides fundamental tools for manipulating images, including cropping, resizing, and rotation.
Image Editing Capabilities
Beyond basic adjustments, Preview allows for image annotation and other minor modifications.
While it won't supplant dedicated software like Photoshop, Preview offers a convenient solution for simple image editing tasks.
Similar to how QuickTime doesn't aim to replace iMovie despite its media editing features, Preview isn’t intended to be a Photoshop alternative.
A Useful Tool for Quick Edits
For rapidly making straightforward changes to images, Preview proves to be remarkably helpful.
It’s an accessible option when more complex editing isn’t required.
The application’s simplicity makes it ideal for users needing quick and uncomplicated image adjustments.
Importing Images into Preview on macOS
This guide details methods for viewing images within the Preview application on a Mac. Preview offers versatile functionality for merging, dividing, annotating, and digitally signing PDFs, alongside image editing capabilities.
Typically, launching an image in Preview is straightforward. A simple double-click on the image file will automatically open it within the application. Should your default file associations have been altered, you can utilize either a Command-click or a right-click on the image file.
Accessing Preview
From the contextual menu, select "Open With" and then choose "Preview." Alternatively, Preview can be initiated directly from the Applications folder or Launchpad.
Another method involves using Spotlight Search. Press Command + Space, type "Preview," and select the application from the search results. Once Preview is open, navigate to File > Open and select the desired image file.
Importing from the Clipboard
Preview also allows importing images directly from your clipboard. With Preview running, choose File > New From Clipboard. This will paste the image into a new Preview window.
After editing an image within Preview, it can be copied back to the clipboard by selecting Edit > Copy. This allows for easy pasting into other applications.
Utilizing Screenshots
For editing screenshots, macOS provides several convenient shortcuts. Press Command+Shift+3 to capture the entire screen, Command+Shift+4 to select a specific area, or Command+Shift+5 for a screenshot of the active window.
These screenshots are saved as .png files on your desktop and can be immediately opened in Preview for editing. Holding the Control key during the screenshot process (e.g., Command+Ctrl+Shift+3) saves the image directly to the clipboard, enabling quick import via File > New From Clipboard.
Image Rotation Techniques
The process of rotating an image is straightforward. Simply utilize the rotate control located on the toolbar, typically positioned in the upper-right corner of the interface, clicking it repeatedly to achieve the desired orientation.
Alternatively, image rotation can be accessed through the Edit menu, where a selection of Rotate or Flip commands are available.
Once the image has been rotated to your satisfaction, ensure the modifications are preserved by selecting File > Save. Consider using File > Duplicate to generate a copy of the image.
This allows you to save the altered version as a new file, while simultaneously retaining the original, unedited image.
Should you wish to discard any applied changes, navigate to the Edit menu and choose Undo. To completely restore the image to its initial state, prior to any editing, select File > Revert To, then choose the original image version.
This action will effectively discard all modifications and return the image to its previously saved condition.
Image Cropping with Preview
The process of cropping an image is straightforward. Preview defaults to a rectangular selection tool, allowing you to begin cropping simply by clicking and dragging directly on the image.
Should the rectangular selection not be active, navigate to the Tools menu and choose Rectangular Selection to enable it.
Initiate a selection by clicking and dragging across the desired portion of the image. This will define the rectangular area you wish to retain.
Following the selection, access the Crop function through the Tools menu. Preview will then isolate the selected area, removing all other parts of the image.
Remember to save your modifications by selecting File > Save after cropping is complete.
This ensures that the cropped image is permanently stored.
Image Resizing Techniques
To modify an image's dimensions, navigate to Tools and then select Adjust Size. This action will open the Resize dialog box, providing options for altering the image's size.
The tool accommodates a variety of measurement units, notably pixels. By default, resizing is performed proportionally, preserving the original aspect ratio. This prevents distortion, ensuring the image doesn't appear stretched or compressed.
Benefits of Image Resizing
Resizing tools are particularly effective for reducing image file sizes and their visual prominence. This is beneficial for optimizing web pages and conserving storage space.
However, it's generally not recommended to enlarge images. Increasing the size of an image typically results in a noticeable reduction in quality.
- Enlarging an image introduces pixelation.
- The resulting image appears blurry and less detailed.
- Maintaining original quality is crucial for professional results.
Therefore, it’s almost always preferable to work with an image that is already of sufficient resolution rather than attempting to upscale it.
Image Annotation Features
The Preview application offers a suite of image annotation tools, mirroring those available for PDF documents. These tools become accessible when you click the "Show Markup Toolbar" button, located in the upper-right portion of the application window.
Alternatively, you can navigate to the Tools menu, select Annotate, and then choose the desired annotation tool from the submenu.
Using the Annotation Tools
Once a tool is selected, it will supersede the standard "rectangular selection" tool. Clicking within the image area then allows you to add textual notes, draw lines, emphasize sections, construct geometric shapes, or insert directional arrows.
The specific action performed depends entirely on the tool currently chosen.
Here's a visual representation of the process:
Color and Gamma Adjustments in PreviewRelated: Utilizing QuickTime on Your Mac for Video and Audio Editing
The Preview application, included with macOS, provides functionality for modifying an image’s color levels or gamma. Access this feature by navigating to Tools > Adjust Color. This opens a panel with various color settings you can manipulate.
The panel features a comprehensive color level graph for modification, alongside sliders controlling exposure, contrast, highlights, shadows, saturation, temperature, tint, sepia, and sharpness. These tools are beneficial for correcting image colors or applying stylistic filters, such as the vintage sepia effect popularized by Instagram.
Even without a complete understanding of each option, adjustments can be made intuitively. The image updates dynamically as you move the sliders, providing a real-time preview of the changes. Experimentation is encouraged to discover the effects of each setting.
Preview’s capabilities extend beyond simple viewing. It can handle multiple image files simultaneously, allowing for quick transitions between them, effectively creating a slideshow.
To achieve this, select several images in Finder by holding Shift while clicking. Then, either Command-click or right-click on the selection and choose to open them in Preview. A sidebar will appear, displaying thumbnails of all opened images.
You can navigate between images using the arrow keys or by directly clicking on the thumbnails in the sidebar for rapid viewing.
Image Source: Quentin Meulepas via Flickr