Unexpected MATLAB expression- can you help?

I'm testing out the below code but I keep on getting this error: Error: File: program1.m Line: 1 Column: 8 Unexpected MATLAB expression. How do I fix this problem?

 %(Image Enhancement)
image=imread('thumb.jpg');
function [final]=fftenhance(image,f) I = 255-double(image);
[w,h] = size(I);
%out = I;
w1=floor(w/32)*32; h1=floor(h/32)*32;
inner = zeros(w1,h1);
for i=1:32:w1
for j=1:32:h1
a=i+31;
b=j+31;
F=fft2( I(i:a,j:b) ); factor=abs(F).^f;
block = abs(ifft2(F.*factor)); larv=max(block(:));
if larv==0
larv=1; end;
block= block./larv;
inner(i:a,j:b) = block; end;
end;
final=inner*255;
final=histeq(uint8(final));

Answer 1

[Stephen23]

The first line of your code above has a commented-out line for the first line, so there must be something that you are not showing us which is causing this error message.

Nonetheless, here are a few tips for getting your code working:

• Do not use the variable name image, as this is the name of a very useful inbuilt function image.
• It is an error to write both a script and a function in one file, which is what you are trying to do here. The first code line image=imread('thumb.jpg');, without a preceding function declaration, tells MATLAB that this is a script. Then you follow this with a function declaration, thus making both a script and a function in one file. It is not possible to do both in one file: either the whole file must be one script (no functions) or the file can consist only of functions.
• Do not use i and j as variable names, as these are the names of the inbuilt imaginary unit.

[Margery]

Thank you for the tips. Unfortunately I haven't figure it out yet. This is the page I got the code from https://github.com/SabaAnsari/FingerPrint-Recognition/blob/master/fftenhance.m

[Stephen23]

Thanks for the link. The problem is not that code, but your code, for the reasons that I pointed out (and perhaps others too). If you upload your actual Mfile then we can tell you how to make it work correctly (use the paperclip button above the textbox to upload)

[John D'Errico]

The problem is simple. You don't understand what scripts are and how they are different from functions.

You have an m-file script file (one that does NOT start with a function declaration.)

Scripts do NOT allow sub-functions. So a script does not allow you to have a function declaration that begins after the first executable line. Comments are allowed to precede the function declaration.

So, looking at the code in that link you posted, you took the code that you got, then added the line:

image=imread('thumb.jpg');

to the beginning (and the comment too.) Then you renamed the file to program1.m.

That was just a bad idea.

An m-file function in matlab should have the same name that it is given in the header of the function. Thus here, the function name and the name of that m-file SHOULD have been fftenhance, as we see here:

function [final]=fftenhance(image,f)

[Margery]

Thank you! I figured it out!

[rahul hanot]

fftehance fuction is having 2 argument one is image and wht is the 2nd arrugument f can anyone plz tellme the value of f

Answer 2

[Daniel Quiteque]

Hello people!

Please, can some of you help me?

aim trying to code this script, but alwau=ys give me a wrong.

% Demonstration of BPSK tx/rx chain (waveform simulation)

clearvars ; clc; clear all

N=100000;%Number of symbols to transmit

EbN0dB = -4:2:10; % Eb/N0 range in dB for simulation

L=16;%oversampling factor,L=Tb/Ts(Tb=bit period,Ts=sampling period)

%if a carrier is used, use L = Fs/Fc, where Fs >> 2xFc

Fc=800; %carrier frequency

Fs=L*Fc;%sampling frequency

EbN0lin = 10.^(EbN0dB/10); %converting dB values to linear scale

BER = zeros(length(EbN0dB),1); %for SER values for each Eb/N0

ak = rand(N,1)>0.5; %random symbols from 0's and 1's

[s_bb,t]= bpsk_mod(ak,L); %BPSK modulation(waveform) - baseband

s = s_bb.*cos(2*pi*Fc*t/Fs); %with carrier

%Waveforms at the transmitter

subplot(2,2,1);plot(t,s_bb);%baseband wfm zoomed to first 10 bits

xlabel('t(s)');

ylabel('s_{bb}(t)-baseband');

xlim([0,10*L]);

subplot(2,2,2);plot(t,s); %transmitted wfm zoomed to first 10 bits

xlabel('t(s)'); ylabel('s(t)-with carrier');xlim([0,10*L]);

%signal constellation at transmitter

subplot(2,2,3);plot(real(s_bb),imag(s_bb),'o');

xlim([-1.5 1.5]); ylim([-1.5 1.5]);

for i=1:length(EbN0dB),

Eb=L*sum(abs(s).2)/length(s); %signal energy

N0= Eb/EbN0lin(i); %Find the noise spectral density

n = sqrt(N0/2)*randn(1,length(s));%computed noise

r = s + n;%received signal with noise

r_bb = r.*cos(2*pi*Fc*t/Fs);%recovered baseband signal

ak_cap = bpsk_demod(r_bb,L);%baseband correlation demodulator

BER(i) = sum(ak=ak_cap)/N;%Symbol Error Rate Computation

%Received signal waveform zoomed to first 10 bits

subplot(2,2,4);plot(t,r);%received signal (with noise)

xlabel('t(s)'); ylabel('r(t)');xlim([0,10*L]);

pause;%wait for keypress

end

theoreticalBER = 0.5*erfc(sqrt(EbN0lin));%Theoretical bit error rate

figure;semilogy(EbN0dB,BER,'k*'); %simulated BER

hold on;semilogy(EbN0dB,theoreticalBER,'r-');

xlabel('E_b/N_0 (dB)'); ylabel('Probability of Bit Error - P_b');

legend('Simulated', 'Theoretical');grid on;

title(['Probability of Bit Error for BPSK modulation']);

[Steven Lord]

Since this doesn't seem related to the original question, you should ask this as a separate question using the Ask link near the top of this page.