Mercurial > octave-libgccjit
view scripts/image/private/__imread__.m @ 18964:a0c514c243f6 default tip @
maint: Use Octave coding conventions for %!test in graphics.cc.
* graphics.cc: Use Octave coding conventions for %!test in graphics.cc.
author | Rik <rik@octave.org> |
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date | Mon, 28 Jul 2014 08:36:39 -0700 |
parents | 15db54c4a572 |
children |
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## Copyright (C) 2013 Carnë Draug ## Copyright (C) 2008-2013 Thomas L. Scofield ## Copyright (C) 2008 Kristian Rumberg ## Copyright (C) 2006 Thomas Weber ## Copyright (C) 2005 Stefan van der Walt ## Copyright (C) 2002 Andy Adler ## ## This file is part of Octave. ## ## Octave is free software; you can redistribute it and/or modify it ## under the terms of the GNU General Public License as published by ## the Free Software Foundation; either version 3 of the License, or (at ## your option) any later version. ## ## Octave is distributed in the hope that it will be useful, but ## WITHOUT ANY WARRANTY; without even the implied warranty of ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU ## General Public License for more details. ## ## You should have received a copy of the GNU General Public License ## along with Octave; see the file COPYING. If not, see ## <http://www.gnu.org/licenses/>. ## This function does all the work of imread. It exists here as private ## function so that imread can use other functions if imformats is ## configured to. It is also needed so that imformats can create a ## function handle for it. ## Author: Carnë Draug <carandraug@octave.org> ## Author: Thomas L. Scofield <scofield@calvin.edu> ## Author: Kristian Rumberg <kristianrumberg@gmail.com> ## Author: Thomas Weber <thomas.weber.mail@gmail.com> ## Author: Stefan van der Walt <stefan@sun.ac.za> ## Author: Andy Adler function varargout = __imread__ (filename, varargin) if (nargin < 1) print_usage ("imread"); elseif (! ischar (filename)) error ("imread: FILENAME must be a string"); endif ## keep track of the varargin offset we're looking at each moment offset = 1; ## It is possible for an file with multiple pages to have very different ## images on each page. Specifically, they may have different sizes. Because ## of this, we need to first find out the index of the images to read so ## we can set up defaults for things such as PixelRegion later on. options = struct ("index", 1); # default image index ## Index is the only option that can be defined without the parameter/value ## pair style. When defining it here, the string "all" is invalid though. ## Also, for matlab compatibility, if index is defined both as an option here ## and parameter/value pair, silently ignore the first. if (nargin >= offset + 1 && ! ischar (varargin{offset})) if (! is_valid_index_option (options.index)) error ("imread: IDX must be a numeric vector"); endif options.index = varargin{offset}; offset++; endif if (rem (numel (varargin) - offset + 1, 2) != 0) error ("imread: no pair for all arguments (odd number left over)"); endif ## Check key/value options. indexes = cellfun ("isclass", varargin, "char"); indexes(indexes) &= ismember (tolower (varargin(indexes)), {"frames", "index"}); indexes = find (indexes); if (indexes) options.index = varargin{indexes+1}; if (! (is_valid_index_option (options.index)) && ! (ischar (options.index) && strcmpi (options.index, "all"))) error ("imread: value for %s must be a vector or the string `all'"); endif endif ## Use information from the first image to be read to set defaults. if (ischar (options.index) && strcmpi (options.index, "all")) info = __magick_ping__ (filename, 1); else info = __magick_ping__ (filename, options.index(1)); endif ## Set default for options. options.region = {1:1:info.rows 1:1:info.columns}; for idx = offset:2:(numel (varargin) - offset + 1) switch (tolower (varargin{idx})) case {"frames", "index"} ## Do nothing. This options were already processed before the loop. case "pixelregion", options.region = varargin{idx+1}; if (! iscell (options.region) || numel (options.region) != 2) error ("imread: value for %s must be a 2 element cell array", varargin{idx}); endif for reg_idx = 1:2 if (numel (options.region{reg_idx}) == 3) ## do nothing elseif (numel (options.region{reg_idx}) == 2) options.region{reg_idx}(3) = options.region{reg_idx}(2); options.region{reg_idx}(2) = 1; else error ("imread: range for %s must be a 2 or 3 element vector", varargin{idx}); endif options.region{reg_idx} = floor (options.region{reg_idx}(1)): ... floor (options.region{reg_idx}(2)): ... floor (options.region{reg_idx}(3)); endfor if (options.region{1}(end) > info.rows) error ("imread: end ROWS for PixelRegions option is larger than image height"); elseif (options.region{2}(end) > info.columns) error ("imread: end COLS for PixelRegions option is larger than image width"); endif case "info", ## We ignore this option. This parameter exists in Matlab to ## speed up the reading of multipage TIFF by passing a structure ## that contains information about the start on the file of each ## page. We can't control it through GraphicsMagic but at least ## we allow to load multiple pages with one command. otherwise error ("imread: invalid PARAMETER `%s'", varargin{idx}); endswitch endfor [varargout{1:nargout}] = __magick_read__ (filename, options); endfunction ## Tests if the value passed to the Index or Frames is valid. This option ## can be defined in two places, but only in one place can it also be the ## string "all" function bool = is_valid_index_option (arg) bool = isvector (arg) && isnumeric (arg) && isreal (arg); endfunction