Converting JPG images into a cell arrays

5 views (last 30 days)
I have the following code i want to convert images jpg (TrainingData) into cell arrays ,where each cell containing a 28-by-28 matrix representing a synthetic image of fingerprint
dataDir= fullfile('Data/');
exts = {'.jpg','.png','.tif','BMP'};
imds = imageDatastore(fullfile(dataDir),...
[TrainData, TestData] = splitEachLabel(imds, 0.5);
for i = 1:numImages
img = readimage(TrainData, i);
img = imbinarize(img);

Accepted Answer

Walter Roberson
Walter Roberson on 24 Oct 2020
Edited: Walter Roberson on 25 Oct 2020
sz = size(img);
RB = 28; CB = 28;
NRB = floor(sz(1)/RB);
LOR = sz(1) - NRB*RB;
NCB = floor(sz(2)/CB);
LOC = sz(2) - NCB*CB;
if LOR ~= 0
rbs = [RB * ones(1,NRB), LOR];
rbs = RB * ones(1,NRC);
if LOC ~= 0
cbs = [CB * ones(1,NCB), LOC];
cbs = CB * ones(1,NCB);
tiles = mat2cell(img, rbs, cbs, size(img,3));
See also mat2tiles in the File Exchange
And watch out for the titles that are not 28 x 28. This code does not assume that the image is an exact integer multiple of 28 in each direction, and it does not throw away any partial blocks.
Walter Roberson
Walter Roberson on 25 Oct 2020
You are right, I had a bug in the code. I fixed it above.
Caution: your 400 x 400 image will end up with partial tiles. On each dimension, you have 14 full groups of 28, and then you have partial group of 8 to reach 400. Because of this, some of the blocks in tiles will be 8 x 28, and some will be 28 x 8, and one of them will be 8 x 8.

Sign in to comment.

More Answers (0)

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by