Mat2Cell error when splitting an image up into smaller images

Question

Jason 2019-10-18

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/486118-mat2cell-error-when-splitting-an-image-up-into-smaller-images

评论： Jason 2019-10-20

Hello, i have a large Image (3200 x 14444 pixels). I want to split it into subimages. Im using mat2cell but Im getting the error as shown below.

blockSizeRow=512
blockSizeCol=256

function blockImages = splitImageIntoBlocks(image, blockSizeRow, blockSizeCol)
% blockSizeRow: Rows in block
% blockSizeCol: Columns in block
[nrows, ncols] = size(image);
% Calculate size of each block by rows and columns
nBlocksRow = floor(nrows / blockSizeRow);
nBlocksCol = floor(ncols / blockSizeCol);
rowDist = [blockSizeRow * ones(1, nBlocksRow-1), rem(nrows, nBlocksRow) + blockSizeRow];
colDist = [blockSizeCol * ones(1, nBlocksCol-1), rem(ncols, nBlocksCol) + blockSizeCol];
blockImages = mat2cell(image, rowDist, colDist); 

Error using mat2cell (line 89)
Input arguments, D1 through D2, must sum to each dimension of the input matrix size, [3200  14444].

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Jason 2019-10-18

Hi Walter, I'd rather the last block be smaller so I retain as many partial blocks of the same size as possible

Walter Roberson 2019-10-18

Last block is mod(nrows, blockSizeRow) with nothing added. Just watch out for the case where the size is exactly divisible into blocks: mat2cell is happy to toss in a block of size 0 but you probably do not want those

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Answer 1

Walter Roberson 2019-10-20

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/486118-mat2cell-error-when-splitting-an-image-up-into-smaller-images#answer_397249

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function blockImages = splitImageIntoBlocks(image, blockSizeRow, blockSizeCol)
% blockSizeRow: Rows in block
% blockSizeCol: Columns in block
[nrows, ncols] = size(image);
% Calculate size of each block by rows and columns
nBlocksRow = floor(nrows / blockSizeRow);
nBlocksCol = floor(ncols / blockSizeCol);
rowDist = [blockSizeRow * ones(1, nBlocksRow), mod(nrows, nBlocksRow)];
colDist = [blockSizeCol * ones(1, nBlocksCol), mod(ncols, nBlocksCol)];
%check for case of file image divisible into blocks
if rowDist(end) == 0; rowDist(end) = []; end
if colDist(end) == 0; colDist(end) = []; end
blockImages = mat2cell(image, rowDist, colDist, size(image,3)); 