mathlab image processing

>> img=imread('img01.tif'); >> img1=imread('img01.tif'); >> imwrite(img1,'Im01.png','png'); >> whos img1 Name        Size                 Bytes  Class    Attributes img1      600x591x3            1063800  uint8 >> img2=imread('im01.png'); >> whos im2 >> imfinfo('img01.tif') ans = Filename: 'img01.tif' FileModDate: '01-Февруари-2010 15:57:00' FileSize: 717940 Format: 'tif' FormatVersion: [] Width: 591 Height: 600 BitDepth: 24 ColorType: 'truecolor' FormatSignature: [73 73 42 0] ByteOrder: 'little-endian' NewSubFileType: 0 BitsPerSample: [8 8 8] Compression: 'LZW' PhotometricInterpretation: 'RGB' StripOffsets: [5x1 double] SamplesPerPixel: 3 RowsPerStrip: 147 StripByteCounts: [5x1 double] XResolution: 100 YResolution: 100 ResolutionUnit: 'Inch' Colormap: [] PlanarConfiguration: 'Chunky' TileWidth: [] TileLength: [] TileOffsets: [] TileByteCounts: [] Orientation: 1 FillOrder: 1 GrayResponseUnit: 0.0100 MaxSampleValue: [255 255 255] MinSampleValue: 0 Thresholding: 1 Software: 'Adobe Photoshop CS3 Windows ' DateTime: '2010:02:01 15:56:53 ' ICCProfileOffset: 26718 >> img1.info=imfinfo('img01.tif'); >> img.bytes=img1.info.Width*img1.info.Height*img1.info.BitDepth; >> img.filesize=img1.info.FileSize img = bytes: 8510400 filesize: 717940 >> img.bytes=img1.info.Width*img1.info.Height*img1.info.BitDepth; >> img.filesize=img1.info.FileSize;