Sets image quality between 0 and 100. For lossless optimizations, set quality to 100.
Adjusting quality near 40-50 for large images (>3Mb) generally results in the exact same visual quality and significantly decreased file size.
You can't get %100 original of your image through your CDN Link. Even if you set quality to 100 and select the original format, the returned image will be optimized as lossless. That means no visual difference but significantly reduced file size.
The examples below have the exact same dimensions. However, you can also significantly decrease the file size by adjusting your image size. You won't need a 2000x2000 image for a 100x100 area.