Annotate an image in Preview on Mac
You can use the editing tools in the Markup toolbar to mark up an image file, providing feedback or pointing out something you want to remember.
If the image is on a page in a PDF file and you want to comment on only the image, you can extract the image as a separate image file. See Extract a PDF page as an image for instructions.
If you only want to comment on part of an image that you’ve opened in Preview, you can select part of it, choose Edit > Copy to copy just that part, then choose File > New from Clipboard to create a new file. You can also crop the image to remove areas that you don’t want.
Note: If you annotate an image file, you can’t edit, move or delete the annotations after you save the image. If you think you’ll need to change annotations later, you can convert the image file to a PDF file, then add annotations to the PDF.
In the Preview app
on your Mac, click the Show Markup Toolbar button 
(if the Markup toolbar isn’t showing).Use the tools in the toolbar to mark up the image (or use the Touch Bar).
Tool
Description
Rectangular Selection
Use any of the following shape tools to select an area in an image and then crop, copy or delete:
Rectangular Selection
Elliptical Selection
Lasso Selection
Smart Lasso
Instant Alpha
Remove the background from an image.
Sketch
Sketch a shape using a single stroke.
If your drawing is recognised as a standard shape, it’s replaced by that shape; to use your drawing instead, choose it from the palette that’s shown.
Draw
Draw a shape using a single stroke. Press your finger more firmly on the trackpad to draw with a heavier, darker line.
Note: Unlike the Sketch tool, the Draw tool doesn’t recognise standard shapes.
This tool appears only on computers with a Force Touch trackpad.
Shapes
Click a shape, then drag it where you want. To resize the shape, use the blue handles. If it has green handles, use them to alter the shape.
You can zoom and highlight shapes using these tools:
Loupe
Highlight
: Drag the highlight where you want. To resize it, use the blue handles.
See Rotate and modify shapes added to a PDF for more options.
Text
Type your text, then drag the text box where you want.
Sign
If signatures are listed, click one, then drag it where you want. To resize it, use the blue handles.
To create a new signature:
Using your trackpad: Click Trackpad, click the text as prompted, sign your name on the trackpad using your finger, click any key when you’ve finished, then click Done. If you don’t like the results, click Clear, then try again.
If your trackpad supports it, press your finger more firmly on the trackpad to sign with a heavier, darker line.
Using your computer’s built-in camera: Click Camera. Hold your signature (on white paper) facing the camera so that your signature is level with the blue line in the window. When your signature appears in the window, click Done. If you don’t like the results, click Clear, then try again.
Using your iOS or iPadOS device: Click Select Device to choose a device (if more than one is available). On your device, use your finger or Apple Pencil (on iPad) to sign your name, then click Done. If you don’t like the results, click Clear, then try again.
Your devices must meet Continuity system requirements. See the Apple Support article System requirements for Continuity on Mac, iPhone, iPad, iPod touch and Apple Watch.
See Fill out a PDF form.
Adjust colour
Change values for an image’s exposure, contrast, saturation, tint and more.
To have the values automatically adjusted, click Auto Levels. To return to the original values, click Reset All.
Adjust size
Change an image’s size and resolution.
Shape Style
Change the thickness and type of lines used in a shape, and add a shadow.
Border Colour
Change the colour of the lines used in a shape.
Fill Colour
Change the colour that’s used inside a shape.
Text Style
Change the font or the font style and colour.
Annotate
Annotate the item by sketching or drawing on it using your nearby iPhone
Your devices must meet Continuity system requirements. See the Apple Support article System requirements for Continuity on Mac, iPhone, iPad, iPod touch and Apple Watch.
