/src/support/z_media_preview.erl
Erlang | 446 lines | 342 code | 46 blank | 58 comment | 19 complexity | 9cf8e3eeae6865686dc35ed938d322c9 MD5 | raw file
1%% @author Marc Worrell <marc@worrell.nl> 2%% @copyright 2009 Marc Worrell 3%% Date: 2009-03-02 4%% @doc Make still previews of media, using image manipulation functions. Resize, crop, gray, etc. 5%% This uses the command line imagemagick tools for all image manipulation. 6%% This code is adapted from PHP GD2 code, so the resize/crop could've been done more efficiently, but it works :-) 7 8%% Copyright 2009 Marc Worrell 9%% 10%% Licensed under the Apache License, Version 2.0 (the "License"); 11%% you may not use this file except in compliance with the License. 12%% You may obtain a copy of the License at 13%% 14%% http://www.apache.org/licenses/LICENSE-2.0 15%% 16%% Unless required by applicable law or agreed to in writing, software 17%% distributed under the License is distributed on an "AS IS" BASIS, 18%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 19%% See the License for the specific language governing permissions and 20%% limitations under the License. 21 22-module(z_media_preview). 23-author("Marc Worrell <marc@worrell.nl"). 24 25%% interface functions 26-export([ 27 convert/4, 28 size/3, 29 can_generate_preview/1, 30 out_mime/2, 31 string2filter/2, 32 cmd_args/3, 33 calc_size/7 34]). 35 36-define(MAX_WIDTH, 5000). 37-define(MAX_HEIGHT, 5000). 38 39-include_lib("zotonic.hrl"). 40 41 42%% @spec convert(InFile, OutFile, Filters, Context) -> ok | {error, Reason} 43%% @doc Convert the Infile to an outfile with a still image using the filters. 44%% @todo Check if the conversion has been done 45%% @todo Check if the target /= source 46convert(InFile, OutFile, Filters, Context) -> 47 case z_media_identify:identify(InFile, Context) of 48 {ok, FileProps} -> 49 {mime, Mime} = proplists:lookup(mime, FileProps), 50 case can_generate_preview(Mime) of 51 true -> 52 OutMime = z_media_identify:guess_mime(OutFile), 53 {EndWidth, EndHeight, CmdArgs} = cmd_args(FileProps, Filters, OutMime), 54 z_utils:assert(EndWidth < ?MAX_WIDTH, image_too_wide), 55 z_utils:assert(EndHeight < ?MAX_HEIGHT, image_too_high), 56 Args1 = lists:flatten(z_utils:combine(32, CmdArgs)), 57 Cmd = ["convert ", z_utils:os_filename(InFile++infile_suffix(Mime)), " ", Args1, " ", z_utils:os_filename(OutFile)], 58 file:delete(OutFile), 59 ok = filelib:ensure_dir(OutFile), 60 Result = z_media_preview_server:exec(lists:flatten(Cmd), OutFile), 61 case filelib:is_regular(OutFile) of 62 true -> 63 ok; 64 false -> 65 ?LOG("convert cmd ~p failed, result ~p", [Cmd, Result]), 66 {error, "Error during convert."} 67 end; 68 false -> 69 {error, "Can not convert "++Mime} 70 end; 71 {error, Reason} -> 72 {error, Reason} 73 end. 74 75%% Return the ImageMagick input-file suffix. 76%% @spec infile_suffix(Mime) -> Suffix::string() 77infile_suffix(<<"image/gif">>) -> []; 78infile_suffix(_) -> "[0]". 79 80 81%% @spec size(MediaRef, Filters, Context) -> {size, Width, Height, ResizedMime} | {error, Reason} 82%% MediaRef = Filename | MediaProps 83%% @doc Calculate the size of the resulting image. 84size([{_Prop, _Value}|_] = Props, Filters, _Context) -> 85 size_props(Props, Filters); 86size(InFile, Filters, Context) -> 87 case z_media_identify:identify(InFile, Context) of 88 {ok, FileProps} -> 89 size_props(FileProps, Filters); 90 {error, Reason} -> 91 {error, Reason} 92 end. 93 94 95 size_props(FileProps, Filters) -> 96 {mime, Mime} = proplists:lookup(mime, FileProps), 97 case can_generate_preview(Mime) of 98 true -> 99 {width, ImageWidth} = proplists:lookup(width, FileProps), 100 {height, ImageHeight} = proplists:lookup(height, FileProps), 101 {orientation, Orientation} = proplists:lookup(orientation, FileProps), 102 103 ReqWidth = z_convert:to_integer(proplists:get_value(width, Filters)), 104 ReqHeight = z_convert:to_integer(proplists:get_value(height, Filters)), 105 {CropPar,_Filters1} = fetch_crop(Filters), 106 {ResizeWidth,ResizeHeight,CropArgs} = calc_size(ReqWidth, ReqHeight, ImageWidth, ImageHeight, CropPar, Orientation, is_enabled(upscale, Filters)), 107 case CropArgs of 108 none -> 109 case is_enabled(extent, Filters) of 110 true when is_integer(ReqWidth) andalso is_integer(ReqHeight) -> 111 {size, ReqWidth, ReqHeight, "image/jpeg"}; 112 _ -> 113 {size, ResizeWidth, ResizeHeight, "image/jpeg"} 114 end; 115 {_CropL, _CropT, CropWidth, CropHeight} -> {size, CropWidth, CropHeight, "image/jpeg"} 116 end; 117 false -> 118 {error, {no_preview_for_mimetype, Mime}} 119 end. 120 121 122%% @spec can_generate_preview(Mime) -> true | false 123%% @doc Check if we can generate a preview image of the given mime type 124can_generate_preview(B) when is_binary(B) -> can_generate_preview(binary_to_list(B)); 125can_generate_preview("image/" ++ _) -> true; 126can_generate_preview("application/pdf") -> true; 127can_generate_preview("application/postscript") -> true; 128can_generate_preview(_Mime) -> false. 129 130 131%% @doc Map filters to commandline options 132cmd_args(FileProps, Filters, OutMime) -> 133 {width, ImageWidth} = proplists:lookup(width, FileProps), 134 {height, ImageHeight} = proplists:lookup(height, FileProps), 135 {mime, Mime0} = proplists:lookup(mime, FileProps), 136 Mime = z_convert:to_list(Mime0), 137 {orientation, Orientation} = proplists:lookup(orientation, FileProps), 138 ReqWidth = proplists:get_value(width, Filters), 139 ReqHeight = proplists:get_value(height, Filters), 140 {CropPar,Filters1} = fetch_crop(Filters), 141 {ResizeWidth,ResizeHeight,CropArgs} = calc_size(ReqWidth, ReqHeight, ImageWidth, ImageHeight, CropPar, Orientation, is_enabled(upscale, Filters)), 142 Filters2 = [ {make_image, Mime}, 143 {correct_orientation, Orientation}, 144 {resize, ResizeWidth, ResizeHeight, is_enabled(upscale, Filters)}, 145 {crop, CropArgs}, 146 {colorspace, "RGB"} | Filters1], 147 Filters3 = case {CropArgs,is_enabled(extent, Filters)} of 148 {none,true} -> Filters2 ++ [{extent, ReqWidth, ReqHeight}]; 149 _ -> Filters2 150 end, 151 Filters4 = case is_blurred(Filters3) of 152 true -> Filters3; 153 false -> case Mime of 154 "image/gif" -> Filters3; 155 "image/png" -> Filters3; 156 _ -> Filters3 ++ [sharpen_small] 157 end 158 end, 159 Filters5 = case proplists:get_value(background, Filters4) of 160 undefined -> default_background(OutMime) ++ Filters4; 161 _ -> Filters4 162 end, 163 164 {EndWidth,EndHeight,Args} = lists:foldl(fun (Filter, {W,H,Acc}) -> 165 {NewW,NewH,Arg} = filter2arg(Filter, W, H), 166 {NewW,NewH,[Arg|Acc]} 167 end, 168 {ImageWidth,ImageHeight,[]}, 169 Filters5), 170 {EndWidth, EndHeight, lists:reverse(Args)}. 171 172 173default_background("image/gif") -> [coalesce]; 174default_background("image/png") -> [coalesce]; 175default_background(_) -> [{background,"white"}, {layers,"flatten"}]. 176 177%% @doc Check if there is a blurring filter that prevents us from sharpening the resulting image 178is_blurred([]) -> false; 179is_blurred([blur|_]) -> true; 180is_blurred([{blur, _}|_]) -> true; 181is_blurred([_|Rest]) -> is_blurred(Rest). 182 183 184is_enabled(_F, []) -> false; 185is_enabled(F, [F|_]) -> true; 186is_enabled(F, [{F, Val}|_]) -> z_convert:to_bool(Val); 187is_enabled(F, [_|R]) -> is_enabled(F, R). 188 189 190%% @spec out_mime(Mime, Options) -> {Mime, Extension} 191%% @doc Return the preferred mime type of the image generated by resizing an image of a certain type and size. 192out_mime("image/gif", _) -> 193 %% gif is gif, daar kan je gif op innemen 194 {"image/gif", ".gif"}; 195out_mime(_Mime, Options) -> 196 case lists:member("lossless", Options) orelse proplists:is_defined(lossless, Options) of 197 false -> {"image/jpeg", ".jpg"}; 198 true -> {"image/png", ".png"} 199 end. 200 201 202%% @spec filter2arg(Filter, Width, Height) -> {NewWidth, NewHeight, Filter::string} 203%% @doc Map filters to an ImageMagick argument 204filter2arg({make_image, "application/pdf"}, Width, Height) -> 205 RArg = ["-resize ", integer_to_list(Width),$x,integer_to_list(Height)], 206 {Width, Height, RArg}; 207filter2arg(coalesce, Width, Height) -> 208 {Width, Height, "-coalesce"}; 209filter2arg({make_image, _Mime}, Width, Height) -> 210 {Width, Height, []}; 211filter2arg({correct_orientation, Orientation}, Width, Height) -> 212 case Orientation of 213 2 -> {Width, Height, "-flip"}; 214 3 -> {Width, Height, "-rotate 180"}; 215 4 -> {Width, Height, "-flop"}; 216 5 -> {Width, Height, "-transpose"}; 217 6 -> {Width, Height, "-rotate 90"}; 218 7 -> {Width, Height, "-transverse"}; 219 8 -> {Width, Height, "-rotate 270"}; 220 _ -> {Width, Height, []} 221 end; 222filter2arg({background, Color}, Width, Height) -> 223 {Width, Height, ["-background ", $", z_utils:os_escape(Color), $"]}; 224filter2arg({layers, Method}, Width, Height) -> 225 {Width, Height, ["-layers ", $", z_utils:os_escape(Method), $"]}; 226filter2arg({colorspace, Colorspace}, Width, Height) -> 227 {Width, Height, ["-colorspace ", $", z_utils:os_escape(Colorspace), $"]}; 228filter2arg({width, _}, Width, Height) -> 229 {Width, Height, []}; 230filter2arg({height, _}, Width, Height) -> 231 {Width, Height, []}; 232filter2arg({resize, Width, Height, _}, Width, Height) -> 233 {Width, Height, []}; 234filter2arg({resize, EndWidth, EndHeight, false}, Width, Height) 235 when Width =< EndWidth andalso Height =< EndHeight -> 236 % Prevent scaling up, perform an extent instead 237 GArg = "-gravity West", 238 EArg = ["-extent ", integer_to_list(EndWidth),$x,integer_to_list(EndHeight)], 239 % Still thumbnail to remove extra info from the image 240 RArg = ["-thumbnail ", z_utils:os_escape([integer_to_list(EndWidth),$x,integer_to_list(EndHeight),$!])], 241 {EndWidth, EndHeight, [GArg, 32, EArg, 32, RArg]}; 242filter2arg({resize, EndWidth, EndHeight, true}, Width, Height) 243 when Width < EndWidth andalso Height < EndHeight -> 244 % Scale up 245 EArg = ["-resize ", integer_to_list(EndWidth),$x,integer_to_list(EndHeight)], 246 RArg = ["-thumbnail ", z_utils:os_escape([integer_to_list(EndWidth),$x,integer_to_list(EndHeight),$!])], 247 {EndWidth, EndHeight, [EArg, 32, RArg]}; 248filter2arg({extent, EndWidth, EndHeight}, Width, Height) when EndWidth == undefined orelse EndHeight == undefined -> 249 {Width, Height, []}; 250filter2arg({extent, EndWidth, EndHeight}, Width, Height) when Width /= EndWidth orelse Height /= EndHeight -> 251 GArg = "-gravity Center", 252 EArg = ["-extent ", integer_to_list(EndWidth),$x,integer_to_list(EndHeight)], 253 {EndWidth, EndHeight, [GArg, 32, EArg]}; 254filter2arg({resize, EndWidth, EndHeight, _}, _Width, _Height) -> 255 GArg = "-gravity NorthWest", 256 RArg = ["-thumbnail ", z_utils:os_escape([integer_to_list(EndWidth),$x,integer_to_list(EndHeight),$!])], 257 {EndWidth, EndHeight, [GArg, 32, RArg]}; 258filter2arg({crop, none}, Width, Height) -> 259 {Width, Height, []}; 260filter2arg({crop, {CropL, CropT, CropWidth, CropHeight}}, _Width, _Height) -> 261 GArg = "-gravity NorthWest", 262 CArg = ["-crop ", integer_to_list(CropWidth),$x,integer_to_list(CropHeight), 263 $+,integer_to_list(CropL),$+,integer_to_list(CropT)], 264 RArg = "+repage", 265 {CropWidth, CropHeight, [GArg,32,CArg,32,RArg]}; 266filter2arg(grey, Width, Height) -> 267 {Width, Height, "-colorspace Gray"}; 268filter2arg(mono, Width, Height) -> 269 {Width, Height, "-monochrome"}; 270filter2arg(flip, Width, Height) -> 271 {Width, Height, "-flip"}; 272filter2arg(flop, Width, Height) -> 273 {Width, Height, "-flop"}; 274filter2arg(blur, Width, Height) -> 275 filter2arg({blur, 10}, Width, Height); 276filter2arg({blur, Blur}, Width, Height) when is_integer(Blur) -> 277 {Width, Height, ["-blur ", integer_to_list(Blur)]}; 278filter2arg({blur, Blur}, Width, Height) when is_list(Blur) -> 279 case string:tokens(Blur, "x") of 280 [A,B] -> {Width, Height, ["-blur ", ensure_integer(A), $x, ensure_integer(B)]}; 281 [A] -> {Width, Height, ["-blur ", ensure_integer(A)]} 282 end; 283filter2arg(sharpen_small, Width, Height) when Width < 400 andalso Height < 400 -> 284 {Width, Height, "-unsharp 0.3x0.7 "}; % 6x3+1+0 285filter2arg(sharpen_small, Width, Height) -> 286 {Width, Height, []}; 287filter2arg(lossless, Width, Height) -> 288 {Width, Height, []}; 289filter2arg({quality, Q}, Width, Height) -> 290 {Width,Height, ["-quality ",integer_to_list(Q)]}; 291filter2arg({removebg, Fuzz}, Width, Height) -> 292 {Width, Height, ["-matte -fill none -fuzz ", integer_to_list(Fuzz), "% ", 293 "-draw 'matte 0,0 floodfill' ", 294 "-draw 'matte 0,", integer_to_list(Height-1), " floodfill' ", 295 "-draw 'matte ", integer_to_list(Width-1), ",0 floodfill' ", 296 "-draw 'matte ", integer_to_list(Width-1), ",", integer_to_list(Height-1), " floodfill' " 297 ]}; 298% Ignore these (are already handled as other filter args) 299filter2arg(extent, Width, Height) -> 300 {Width, Height, []}; 301filter2arg({extent, _}, Width, Height) -> 302 {Width, Height, []}; 303filter2arg({extent, _, _}, Width, Height) -> 304 {Width, Height, []}; 305filter2arg(upscale, Width, Height) -> 306 {Width, Height, []}. 307 308 309%% @spec fetch_crop(Filters) -> {Crop, Filters} 310%% @doc Split the filters into size/crop and image manipulation filters. 311fetch_crop(Filters) -> 312 {Crop,OtherFilters} = lists:partition( 313 fun (crop) -> true; 314 (F) when is_tuple(F) -> element(1,F) == 'crop'; 315 (_) -> false 316 end, Filters), 317 CropPar = case Crop of 318 [{crop,None}] when None == false; None == undefined; None == ""; None == <<>> -> none; 319 [{crop,Gravity}] -> Gravity; % center or one of the wind directions 320 _ -> none 321 end, 322 {CropPar,OtherFilters}. 323 324 325%%@doc Calculate the size of the resulting image, depends on the crop and the original image size 326calc_size(Width, Height, ImageWidth, ImageHeight, CropPar, Orientation, IsUpscale) when Orientation >= 5 -> 327 calc_size(Width, Height, ImageHeight, ImageWidth, CropPar, 1, IsUpscale); 328 329calc_size(undefined, undefined, ImageWidth, ImageHeight, _CropPar, _Orientation, _IsUpscale) -> 330 {ImageWidth, ImageHeight, none}; 331 332calc_size(Width, undefined, ImageWidth, ImageHeight, CropPar, Orientation, IsUpscale) when CropPar /= none -> 333 calc_size(Width, Width, ImageWidth, ImageHeight, CropPar, Orientation, IsUpscale); 334 335calc_size(undefined, Height, ImageWidth, ImageHeight, CropPar, Orientation, IsUpscale) when CropPar /= none -> 336 calc_size(Height, Height, ImageWidth, ImageHeight, CropPar, Orientation, IsUpscale); 337 338calc_size(undefined, Height, ImageWidth, ImageHeight, none, 1, false) when ImageHeight < Height -> 339 % Image will be extented 340 {ImageWidth, Height, none}; 341 342calc_size(undefined, Height, ImageWidth, ImageHeight, CropPar, Orientation, IsUpscale) -> 343 Width = round((ImageWidth / ImageHeight) * Height), 344 calc_size(Width, Height, ImageWidth, ImageHeight, CropPar, Orientation, IsUpscale); 345 346calc_size(Width, undefined, ImageWidth, ImageHeight, none, 1, false) when ImageWidth < Width -> 347 % Image will be extented 348 {Width, ImageHeight, none}; 349 350calc_size(Width, undefined, ImageWidth, ImageHeight, CropPar, Orientation, IsUpscale) -> 351 Height = round((ImageHeight / ImageWidth) * Width), 352 calc_size(Width, Height, ImageWidth, ImageHeight, CropPar, Orientation, IsUpscale); 353 354calc_size(Width, Height, ImageWidth, ImageHeight, CropPar, _Orientation, false) 355 when CropPar /= none, Width > ImageWidth, Height > ImageHeight -> 356 {Width, Height, none}; 357 358calc_size(Width, Height, ImageWidth, ImageHeight, CropPar, _Orientation, _IsUpscale) -> 359 ImageAspect = ImageWidth / ImageHeight, 360 Aspect = Width / Height, 361 case CropPar of 362 none -> 363 case Aspect > ImageAspect of 364 true -> {ceil(ImageAspect * Height), Height, none}; 365 false -> {Width, ceil(Width / ImageAspect), none} 366 end; 367 _ -> 368 % When we are doing a crop then we have to calculate the 369 % maximum inner bounding box, and not the maximum outer 370 % bounding box for the image 371 {W,H} = case Aspect > ImageAspect of 372 true -> 373 % width is the larger one 374 {Width, Width / ImageAspect}; 375 false -> 376 % height is the larger one 377 {ImageAspect * Height, Height} 378 end, 379 CropL = case CropPar of 380 X when X == north_west; X == west; X == south_west -> 0; 381 X when X == north_east; X == east; X == south_east -> ceil(W - Width); 382 _ -> ceil((W - Width) / 2) 383 end, 384 CropT = case CropPar of 385 Y when Y == north_west; Y == north; Y == north_east -> 0; 386 Y when Y == south_west; Y == south; Y == south_east -> ceil(H - Height); 387 _ -> ceil((H - Height) / 2) 388 end, 389 390 % @todo Prevent scaleup of the image, but preserve the result size 391 % The crop is relative to the original image 392 {ceil(W), ceil(H), {CropL, CropT, Width, Height}} 393 end. 394 395 396%% @spec string2filter(Filter, Arg) -> FilterTuple 397%% @doc Map the list of known filters and known args to atoms. Used when mapping preview urls back to filter args. 398string2filter("crop", []) -> 399 {crop,center}; 400string2filter("crop", Where) -> 401 Dir = case Where of 402 "north" -> north; 403 "north_east" -> north_east; 404 "east" -> east; 405 "south_east" -> south_east; 406 "south" -> south; 407 "south_west" -> south_west; 408 "west" -> west; 409 "north_west" -> north_west; 410 "center" -> center 411 end, 412 {crop,Dir}; 413string2filter("grey",[]) -> 414 grey; 415string2filter("mono",[]) -> 416 mono; 417string2filter("flip",[]) -> 418 flip; 419string2filter("flop",[]) -> 420 flop; 421string2filter("extent",[]) -> 422 extent; 423string2filter("upscale",[]) -> 424 upscale; 425string2filter("blur",[]) -> 426 blur; 427string2filter("blur",Arg) -> 428 {blur,Arg}; 429string2filter("quality", Arg) -> 430 {quality,list_to_integer(Arg)}; 431string2filter("background", Arg) -> 432 {background,Arg}; 433string2filter("lossless", []) -> 434 lossless; 435string2filter("removebg", []) -> 436 {removebg, 5}; 437string2filter("removebg", Arg) -> 438 {removebg, list_to_integer(Arg)}. 439 440 441% simple ceil for positive numbers 442ceil(A) -> round(A + 0.499999). 443%floor(A) -> round(A - 0.499999). 444 445ensure_integer(A) -> 446 integer_to_list(list_to_integer(A)).