1.JPG: a lossy compression using standard methods, 24 bit true color, does not support animation, does not support the transparent color. JPEG compression method is usually lossy compression (lossy compression), that is, during the compression of the image quality will suffer visible damage. After a picture upload and download times, the picture gradually distorted.
2.PNG: format is a lossless data compression, PNG format 8, 24, 32 three forms, eight different transparent PNG supports two forms (alpha index transparent and transparent), does not support 24-bit PNG transparent, the 32-bit PNG 24 based on the increase of the transparent passage 8 (32-24 = 8), 256 thus may exhibit the degree of transparency.
3.BMP: nothing to do with a hardware device image file format, use very wide. It uses a bit map storage format, in addition to the image depth Alternatively, without using any additional compression, thus, a large space occupied by BMP images. BMP file image depth optional lbit, 4bit, 8bit and 24bit. When BMP data file storage, the way the image is scanned from left to right, sequentially from bottom to top.
Space: BMP> PNG> JPG