1, BMP: It is an uncompressed image format, which can retain high image quality, but the file size is relatively large. When saving the book cover picture, you can choose to save the picture in BMP format.
2.PNG: It is a lossless compressed image format, which can maintain high image quality and small file size. When saving a book cover picture, you can choose to save the picture in PNG format.
3.JPEG: It is a widely used image compression format, which can compress images to a smaller file size and retain a higher image quality. When saving a book cover picture, you can choose to save the picture in JPEG format.