how to change resolution of photo on mac

If you are posting a flower photo just to celebrate the arrival of spring, then a much lower quality would probably be fine. If you are posting a flower photo to a botanical encyclopedia website, you probably want it to be fairly high quality so small distinguishing details can be clearly seen.

Always keep in mind what the purpose of the graphic is. When you hit a quality level that is unsatisfactory, then back up to the lowest level that was still good enough for your purposes. If the reduced level looks good enough, then try another reduction. One strategy for selecting the best level is to start with a fairly high quality setting and if it looks OK, try reducing the quality a bit. You should always select the lowest quality that is still suitable for your purpose. Or you might be asked to select a percentage from 0% (lowest quality) to 100% (highest quality). You might be given a number range, for example 0 (lowest quality) to 12 (highest quality). You might just see a few choices like: low, medium, high, or maximum. When you export to JPG from an image editing program, you’ll be prompted to select the quality level you want. It’s easiest to compress a JPG (also called JPEG) because there’s just one thing to consider: quality.

For information about compressing PNGs or GIFs, please scroll down this page. We’ll take a look at how to get the best compression in each of the three file types starting with JPEGs. If you have a simple graphic with few colors and solid areas, then your best choice will be a GIF or PNG-8.

If a similar photo needs to have lossless compression or transparent areas, then a PNG-24 will be required. If your image is a photo with lots of colors or an illustration with gradations and you want to squeeze the file size down, JPEG will probably be your best choice. The more compression, the smaller the file will be and the faster it will load on a webpage.īut first, you’ll need to decide which of the three file formats you want to use. In most image editing applications this is done by the selections you make in the “Save As” or “Export As” dialog box when saving a PNG, JPG, or GIF. The primary way to reduce the file size of an image is by increasing the amount of compression.

How to change resolution of photo on mac