Image compression is either lossy or lossless: Lossy works by discarding information from the original file, and lossless retains all the original data (though, the file size tends to be bigger). There’s a variety of image compression algorithms that take different approaches to reducing file size, and the tools listed below utilize a number of those to minimize the size of your images.
1. WORDPRESS IMAGE OPTIMIZER Optimus reduces the file size of uploaded media files automatically. Depending on the image and format, reductions in size of up to 70% are possible. Several kilobytes can be saved per image—these savings contribute positively to the performance of the blog website. What’s most impressive about the compression technology: the quality of the images is maintained.
2. Imsanity Imsanity automatically resizes huge image uploads down to a size that is more reasonable for display in browser, yet still more than large enough for typical website use. The plugin is configurable with a max width, height and quality. When a contributor uploads an image that is larger than the configured size, Imsanity will automatically scale it down to the configured size and replace the original image. Imsanity also provides a bulk-resize feature to selectively resize previously uploaded images to free up disk space. This plugin is ideal for blogs that do not require hi-resolution original images to be stored and/or the contributors don’t want (or understand how) to scale images before uploading.