You can figure out what the options do by playing with them. It doesn’t matter if you’re not sure what the options do - the image will update in the background as you adjust these sliders, so you can see a preview of your color adjustments in real time. Choose Tools > Adjust Size, then select Resample image. It’s useful for everything from fixing the color levels of an image to applying that old-timey sepia filter Instagram made trendy. In the Preview app on your Mac, open the file you want to change. The pane includes an overall color level graph you can modify as well as sliders for adjusting exposure, contrast, highlights, shadows, saturation, temperature, tint, sepia, and sharpness. Use the options on the pane that appears to adjust various color settings. The built-in Preview application also has a tool for adjusting the color levels or gamma of an image. RELATED: Use Your Mac’s QuickTime App to Edit Video and Audio Files You can then click somewhere in the image to add text, draw a line, highlight an area, create a shape, or insert an arrow - whichever tool you’ve selected. Every tool for pixel-accurate selections. A smart way to move, rotate, and distort. Select a tool and it will replace the default “rectangular selection” tool. Pixelmator Classic Powerful, full-featured image editor for Mac. You can also click the Tools menu, point to Annotate, and select one of these tools in the menu.

Preview includes various image mark-up tools - the same ones that work in PDFs - which you can access by clicking the Show Markup Toolbar button near the top-right corner of the window.

Edit png file on mac