%?THE?FEATURE?IS?BILINEAR-INTERPLOT?THE?SOUCE-IMAGE?TO?GET?A?DESTINATE-IMAGE
%?THE?MAXIMUM?SCALOR?==?5.0?THE?MINIMUM?SCALOR?==?0.2

%?read?source?image?into?memoryand?get?the?primitive?rows?and?cols
I=imread（‘lena.jpg‘）;
[nrowsncols]=size（I）;

%?Next?line?is?the?scale-factorthe?range?is?0.2-5.0
K?=?str2double（inputdlg（‘please?input?scale?factor?（must?between?0.2?-?5.0）‘?‘INPUT?scale?factor‘?1?{‘0.5‘}））;

%?Validating
if?（K??5.0）
????errordlg（‘scale?factor?beyond?permitted?range（0.2?-?5.0）‘?‘ERROR‘）;
????error（‘please?input?scale?factor?（must?between?0.2?-?5.0）‘）;
end

%?display?source?image
imshow（I）;

%?output?image?width?and?height?are?both?scaled?by?factor?K
width?=?K?*?nrows;??????????????????????????????%?well512x512?is?just?for?convenienceyo