Problems with different file sizes when loading and rewriting files to Bitmap

The file size changes because the Bitmap.compression() function compresses the bitmap object (image information loaded in memory) to a file in PNG, JPEG format. Since the function does not store the image as a compression option in the same state as the original file, the file size may rather vary.I think that would be appropriate.

For example, when you open a PNG file with an image editor such as Photoshop and save it as a new PNG file, you can see that the file size varies depending on the option to compress it. You can see it as a similar phenomenon.