function changeScale(linRequest)
% function changeScale(linRequest)
%
% changes the scale of the image pixels depending on user request, and displays new image
%
%  Input
%    linRequest: the requested change (1 = linear, 0 = logarithmic)

global im linScale orig_axis cont marks mark_handles select_status;

if (linScale & (~linRequest))  % requested linear to logarithmic
    im = log(im);
    axes(orig_axis);
    imagesc(im);
    axis xy;
    axis image;
    if (cont)
        cont = 0;
        changeLines(1);
    end
    [numMarks, foo] = size(marks);
    mark_handles = [];
    for i = 1 : numMarks
        r = rectangle('Curvature', [1, 1], 'Position', [marks(i,1), marks(i,2), 1, 1], 'FaceColor', 'g', 'LineWidth', 1);
        mark_handles = [mark_handles; r];    
    end
    linScale = 0;
end

if ((~linScale) & linRequest)  % requested logarithmic to linear
    im = exp(im);
    axes(orig_axis);
    imagesc(im);
    axis xy;
    axis image;
    if (cont)
        cont = 0;
        changeLines(1);
    end
    [numMarks, foo] = size(marks);
    mark_handles = [];
    for i = 1 : numMarks
        r = rectangle('Curvature', [1, 1], 'Position', [marks(i,1), marks(i,2), 1, 1], 'FaceColor', 'g', 'LineWidth', 1);
        mark_handles = [mark_handles; r];    
    end
    linScale = 1;
end    

if (select_status == 1)
    title('Choose points on first boundary by left-clicking, then hit enter');
elseif (select_status == 2)
    title('Choose points on second boundary by left-clicking, then hit enter');
else
    title('Choose points on third boundary by left-clicking, then hit enter');
end