Pictures in PNG format are bigger than pictures in any other format, because they retain the most data, and of course they are clearer and more realistic. You can compare the picture size in JPG format with PNG: large size is of course the most complete, clear and advanced data.
BMP format is only a rough format for temporarily saving pictures, and it is not a standard high-definition picture format (PDF or PNG) that can be widely used on the Internet.
The best and fastest way to convert picture format is to use "format factory" and OK every minute.
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PNG is an image file storage format, which aims to replace GIF and TIFF file formats and add some functions that GIF file format does not have. The name of Portable Network Graphics Format (PNG) comes from the unofficial "PNG's Not GIF", which is a bitmap file storage format pronounced "ping". When storing grayscale images with PNG, the depth of grayscale images can be as high as 16 bits, when storing color images, the depth of color images can be as high as 48 bits, and α channel data can also be stored as high as 16 bits. PNG uses lossless data compression algorithm derived from LZ77. Because of its high compression ratio and small file size, it is generally used in JAVA programs, or web pages or S60 programs.
PNG format pictures are widely used in web design and graphic design because of their high fidelity, transparency and small file size. Due to the bandwidth limitation in network communication, it is impossible to widely use bmp and jpg files with large files in web pages on the premise of ensuring clear and realistic pictures. Gif file is small, but its color is seriously eclipsed, so PNG file has been popular since its birth. Pictures in PNG format are usually used as material by us. In the design process, it is inevitable to search related files. If it is a JPG file, matting is inevitable, which is time-consuming and laborious. Although the gif format is transparent, it is only completely transparent to one or several colors, without considering the influence on the surrounding colors, so the file in PNG format has become our best choice at this time. We often see that the whole page uses the same PNG picture as the background, as well as buttons, navigation bars and so on. It's all taken in one photo. In fact, this is the reason. The reason is that PNG pictures occupy less bandwidth and have vivid colors during downloading, so they can be reused after downloading once.