Rank: 32 based on 814 downloads (last 30 days) and 8 files submitted
photo

Jeff Mather

E-mail
Company/University
The MathWorks, Inc.
Lat/Long
37.890998840332, -110.370498657227

Personal Profile:

I am a software engineer in the Image and Scientific Data Formats team of The MathWorks' Image Processing Group.

Professional Interests:
File Formats, Digital Imaging, Color Science

 

Watch this Author's files

 

Files Posted by Jeff View all
Updated   File Tags Downloads
(last 30 days)
Comments Rating
08 Nov 2010 Adobe Photoshop PSD file reader Functions to read images and get metadata from Adobe Photoshop PSD files. Author: Jeff Mather metadata, images, photoshop, psd, graphics export, graphics import 236 11
  • 4.21739
4.2 | 23 ratings
08 Nov 2010 Screenshot Color Image Histogram Display a histogram showing the color balance of an image. Author: Jeff Mather color, rgbhist imhist color ..., also ididnot get the ..., error in rgbhist at 2..., marker, invalid handle object 160 28
  • 2.9
2.9 | 31 ratings
08 Nov 2010 Screenshot hexdump - A binary file explorer A GUI for file exploration: examine byte addresses, hex/char values. Author: Jeff Mather data import, data export, file, contents, hexadecimal, utilities 10 0
08 Nov 2010 Screenshot Spectral and XYZ Color Functions Label plots with spectra. Convert wavelengths to RGB. Functions for color matching and illuminants. Author: Jeff Mather color, spectrum label color ... 84 13
  • 3.90909
3.9 | 11 ratings
08 Nov 2010 DPX file reader A DPX file parser . Author: Jeff Mather dpx, cineon, graphics import, graphics export, motion picture 27 15
  • 4.4
4.4 | 6 ratings
Comments and Ratings on Jeff's Files View all
Updated File Comment by Comments Rating
07 Feb 2012 Spectral and XYZ Color Functions Label plots with spectra. Convert wavelengths to RGB. Functions for color matching and illuminants. Author: Jeff Mather Guido

Help!
I'm trying to use spectrumLabel for a calculated absorption spectrum.
It works fine from the command window, but I'm not able to put the color axis in a plot which is rendered to a GUI.
Here is the piece of code that I put in the .m file. The plot of the extinction, scattering and absorption spectra are sent to the axes style GUI handles.axes1:
----------------------------
axes(handles.axes1);
plot(wave,qext,wave,qsca,wave,qabs);
title('Spectrum');
xlabel('Wavelength (nm)');
ylabel('Arbitrary units');
spectrumLabel(handles.axes1);
-------------------------------
Apparently, the spectrumLabel is put at the right position but with zero or very small vertical dimension.
Thank you!

01 Jan 2012 Spectral and XYZ Color Functions Label plots with spectra. Convert wavelengths to RGB. Functions for color matching and illuminants. Author: Jeff Mather Li

I got this error information:
"the selected cell cannot be evaluated because it contains an invalid statement".
"??? Input argument "formulary" is undefined."
Any idea why this happen? Thank you!

30 Oct 2011 Color Image Histogram Display a histogram showing the color balance of an image. Author: Jeff Mather Zhang, Dongni

It works well with the modification of Jeff in 29 Apr 2011. Thank you!

04 Sep 2011 Spectral and XYZ Color Functions Label plots with spectra. Convert wavelengths to RGB. Functions for color matching and illuminants. Author: Jeff Mather springface

but there seems to be a scale off. I don't know how to solve that. Please help!

04 Sep 2011 Spectral and XYZ Color Functions Label plots with spectra. Convert wavelengths to RGB. Functions for color matching and illuminants. Author: Jeff Mather springface

Thanks to this excellent work, I've been able to image a spectrum plot with both the characteristic peaks marked in colors and intensity plot shown. The code is as following.

%%%%%%%%%%%%%%%%%%%%%%
function SpecRGB_Intensity(wavelength,intensity, peak_threshold)
% wavelength and intensity are vectors
% the characteristic peaks are chosen if the value of the peak
% is bigger than the peak_threshold.
% by springface

sRGB = spectrumRGB(wavelength);

%% Transform spectrum plot into an image, marked by colors
len_wave = length(wavelength);
len_inten = 1000;
intensity_plot = max(intensity):-max(intensity)/(len_inten-1):0;
wavelength_plot = wavelength;

intensity_num = ones(size(intensity));

for cc = 1: len_wave
    if intensity(cc)>=0
        [C,I] = min(abs(intensity(cc)- intensity_plot));
        intensity_num(cc) = len_inten-I;
    end
end

im_plot = ones(len_inten,len_wave,3);

for cc = 1: len_wave
    im_plot(1:intensity_num(cc),cc,:) = repmat(sRGB(1,cc,:),intensity_num(cc),1);
end

%% mark the non-peak area as black
spec_idx = intensity < peak_threshold;
sRGB(1,spec_idx,:) = zeros(1,sum(spec_idx),3);

%% Plot figures
figure;

whitegap_len = 2;
RGBspec_len = 100;

RGBspec_range = max(intensity)+whitegap_len+RGBspec_len+1:max(intensity)+1;

imagesc(wavelength_plot,[RGBspec_range,intensity_plot],...
    cat(1,repmat(sRGB,RGBspec_len,1),ones(whitegap_len,len_wave,3),im_plot));
set(gca,'YTick',[])
%%%%%%%%%%%%%%%%%%%%%%

Top Tags Applied by Jeff
color, metadata, contents, dicom, graphics export
Files Tagged by Jeff View all
Updated   File Tags Downloads
(last 30 days)
Comments Rating
08 Nov 2010 Adobe Photoshop PSD file reader Functions to read images and get metadata from Adobe Photoshop PSD files. Author: Jeff Mather metadata, images, photoshop, psd, graphics export, graphics import 236 11
  • 4.21739
4.2 | 23 ratings
08 Nov 2010 Screenshot Color Image Histogram Display a histogram showing the color balance of an image. Author: Jeff Mather color, rgbhist imhist color ..., also ididnot get the ..., error in rgbhist at 2..., marker, invalid handle object 160 28
  • 2.9
2.9 | 31 ratings
08 Nov 2010 Screenshot hexdump - A binary file explorer A GUI for file exploration: examine byte addresses, hex/char values. Author: Jeff Mather data import, data export, file, contents, hexadecimal, utilities 10 0
08 Nov 2010 Screenshot Spectral and XYZ Color Functions Label plots with spectra. Convert wavelengths to RGB. Functions for color matching and illuminants. Author: Jeff Mather color, spectrum label color ... 84 13
  • 3.90909
3.9 | 11 ratings
08 Nov 2010 DPX file reader A DPX file parser . Author: Jeff Mather dpx, cineon, graphics import, graphics export, motion picture 27 15
  • 4.4
4.4 | 6 ratings

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