1<?xml version="1.0" encoding="UTF-8"?> 2<!DOCTYPE sect2 PUBLIC "-//OASIS//DTD DocBook XML V4.3//EN" 3 "http://www.docbook.org/xml/4.3/docbookx.dtd"> 4<!-- section history: 5 2008-01-18 lexa: further enhancements to filter description for en, de 6 2007-12-27 lexa: reviewed for color management enhancements 7 2007-05-22 Added Spanish translation by AntI 8 2007-03-18 ude: Re-arranged color proof options 9 2005-12-21 julien: Created en;fr; the "profile" section needs more information 10--> 11<sect2 id="gimp-display-filter-dialog"> 12 <title>Display Filters</title> 13 14 <indexterm> 15 <primary>Color</primary> 16 <secondary>Color display</secondary> 17 </indexterm> 18 <para> 19 This command shows a dialog window when executed. This window can be used 20 to manage the display filters and their options. Display filters are not 21 to be confused with the filters in the <guimenu>filters</guimenu>-menu. 22 Display filters do not alter the image data, but only one display of it. 23 You can imagine display filters like big panes before your screen. They 24 change your perception of the image. This can be useful for things like 25 soft proofing prints, controlling the color management but also simulation 26 of color deficient vision. 27 </para> 28 29 <sect3> 30 <title>Activating the Command</title> 31 <para> 32 You can access this command from the image menubar through 33 <menuchoice> 34 <guimenu>View</guimenu> 35 <guimenuitem>Display Filters…</guimenuitem> 36 </menuchoice>. 37 </para> 38 </sect3> 39 40 <sect3> 41 <title>Description of the <quote>Display Filters</quote> Dialog</title> 42 <figure> 43 <title> 44 The <quote>Color Display Filters</quote> dialog 45 </title> 46 <mediaobject> 47 <imageobject> 48 <imagedata format="PNG" 49 fileref="images/menus/view/display-filters.png"/> 50 </imageobject> 51 </mediaobject> 52 </figure> 53 <para> 54 This dialog has two small selectboxes. The left selectbox displays the 55 <guilabel>Available Filters</guilabel>. You can move a filter to the 56 right selectbox by selecting it and clicking on the 57 <guibutton>right arrow</guibutton> button. The 58 <guilabel>Active Filters</guilabel> window on the right displays 59 filters you have chosen and which will be applied if the adjacent box 60 is checked. You can move filters from the right selectbox to the left 61 selectbox by using the <guibutton>left arrow</guibutton> button. If you 62 select a filter by clicking on its name, its options are displayed 63 below the two selectboxes, in the 64 <guilabel>Configure Selected Filter</guilabel> area. 65 </para> 66 <itemizedlist> 67 <listitem> 68 <para> 69 <phrase>Simulation of deficient vision</phrase> 70 (<xref linkend="gimp-deficient-vision"/>; 71 <xref linkend="gimp-contrast-dialog"/>) 72 </para> 73 </listitem> 74 <listitem> 75 <para> 76 <phrase>Digital photography helper</phrase> 77 (<xref linkend="gimp-display-filter-clip-warning"/>) 78 </para> 79 </listitem> 80 <listitem> 81 <para> 82 <phrase>Others</phrase> (<xref linkend="gimp-gamma-dialog"/>) 83 </para> 84 </listitem> 85 </itemizedlist> 86 </sect3> 87 88 <sect3 id="gimp-deficient-vision"> 89 <title>Color Deficient Vision</title> 90 <indexterm> 91 <primary>Color</primary> 92 <secondary>Deficient vision</secondary> 93 </indexterm> 94 <para> 95 The images you create, we hope, will be seen by many people on many 96 different systems. The image which looks so wonderful on your screen may 97 look somewhat different to people with sight deficiencies or on a screen 98 with different settings from yours. Some information might not even be 99 visible. 100 </para> 101 <figure> 102 <title> 103 Description of the <quote>Color Deficient Vision</quote> dialog 104 </title> 105 <mediaobject> 106 <imageobject> 107 <imagedata format="PNG" 108 fileref="images/menus/view/display-filters/color-deficient-vision.png"/> 109 </imageobject> 110 </mediaobject> 111 </figure> 112 113 <sect4> 114 <title>Options</title> 115 <variablelist> 116 <varlistentry> 117 <term>Color Deficiency Type</term> 118 <listitem> 119 <para> 120 In this drop-down menu you can select from among: 121 </para> 122 <variablelist> 123 <varlistentry> 124 <term> 125 Protanopia<footnote> 126 <para> 127 Greek: 128 <foreignphrase>proto</foreignphrase>: first (color in 129 the <link linkend="glossary-colormodel">RGB Color 130 System</link>): 131 <foreignphrase>an</foreignphrase>: negation; 132 <foreignphrase>op</foreignphrase>: eye, vision. 133 </para> 134 </footnote> (insensitivity to red) 135 </term> 136 <listitem> 137 <para> 138 Protanopia is a visual deficiency of the color red. It's 139 the well-known daltonism (red-green color blindness). 140 Daltonism occurs fairly frequently in the population. 141 </para> 142 <para> 143 Protanopia is actually more complex than this; a person 144 with this problem cannot see either red or green, although 145 he is still sensitive to yellow and blue. In addition, he 146 has a loss of luminance perception and the hues shift 147 toward the short wavelengths. 148 </para> 149 </listitem> 150 </varlistentry> 151 <varlistentry> 152 <term>Deuteranopia (insensivity to green)</term> 153 <listitem> 154 <para> 155 With deuteranopia, the person has a deficiency in green 156 vision. Deuteranopia is actually like protanopia, because 157 the person has a loss of red and green perception, but he 158 has no luminance loss or hue shift. 159 </para> 160 </listitem> 161 </varlistentry> 162 <varlistentry> 163 <term>Tritanopia (insensitivity to blue)</term> 164 <listitem> 165 <para> 166 With tritanopia, the person is deficient in blue and 167 yellow perception, although he is still sensitive to red 168 and green. He lacks some perception of luminance, and the 169 hues shift toward the long wavelengths. 170 </para> 171 </listitem> 172 </varlistentry> 173 </variablelist> 174 </listitem> 175 </varlistentry> 176 </variablelist> 177 </sect4> 178 179 <sect4> 180 <title>Examples</title> 181 <figure> 182 <title>Example of protanopia</title> 183 <mediaobject> 184 <imageobject> 185 <imagedata format="PNG" 186 fileref="images/menus/view/display-filters/protanopia-normal.png"/> 187 </imageobject> 188 <caption> 189 <para>Original image</para> 190 </caption> 191 </mediaobject> 192 <mediaobject> 193 <imageobject> 194 <imagedata format="PNG" 195 fileref="images/menus/view/display-filters/protanopia-filtered.png"/> 196 </imageobject> 197 <caption> 198 <!-- 199 As you can see, a red-blind person cannot see the red (255,0,0) 200 text on a black (0,0,0) background. You have to change the text 201 color. Daltonism occurs fairly frequently in the population. 202 --> 203 <para> 204 A red-blind person cannot see the red (255,0,0) text on a black 205 (0,0,0) background. 206 </para> 207 </caption> 208 </mediaobject> 209 </figure> 210 <figure> 211 <title> 212 Examples of the three types of vision deficiencies in one image 213 </title> 214 <mediaobject> 215 <imageobject> 216 <imagedata format="PNG" 217 fileref="images/menus/view/display-filters/sight-defects_normal-view.png"/> 218 </imageobject> 219 <caption> 220 <para>Normal vision</para> 221 </caption> 222 </mediaobject> 223 <mediaobject> 224 <imageobject> 225 <imagedata format="PNG" 226 fileref="images/menus/view/display-filters/sight-defects_protanopia.png"/> 227 </imageobject> 228 <caption> 229 <para>Protanopia</para> 230 </caption> 231 </mediaobject> 232 <mediaobject> 233 <imageobject> 234 <imagedata format="PNG" 235 fileref="images/menus/view/display-filters/sight-defects_deuteranopia.png"/> 236 </imageobject> 237 <caption> 238 <para> 239 Deuteranopia; in deuteranopia, yellow is shifted toward red. 240 </para> 241 </caption> 242 </mediaobject> 243 <mediaobject> 244 <imageobject> 245 <imagedata format="PNG" 246 fileref="images/menus/view/display-filters/sight-defects_tritanopia.png"/> 247 </imageobject> 248 <caption> 249 <para> 250 Tritanopia; in tritanopia, green is slightly represented in the 251 blue range. 252 </para> 253 </caption> 254 </mediaobject> 255 </figure> 256 </sect4> 257 </sect3> 258 259 <sect3 id="gimp-gamma-dialog"> 260 <title>Gamma</title> 261 <indexterm> 262 <primary>Gamma</primary> 263 </indexterm> 264 <para> 265 <figure> 266 <title>The <quote>Gamma</quote> dialog</title> 267 <mediaobject> 268 <imageobject> 269 <imagedata format="PNG" 270 fileref="images/menus/view/display-filters/gamma.png"/> 271 </imageobject> 272 </mediaobject> 273 </figure> 274 </para> 275 <para> 276 The correspondence between electrical intensity and color brightness 277 is not exact and it depends upon the device (the camera, the scanner, 278 the monitor, etc.). <quote>Gamma</quote> is a coefficient used to 279 correct this correspondence. Your image must be visible in both dark 280 and bright areas, even if it is displayed on a monitor with too much 281 luminence or not enough. The <quote>Gamma</quote> Display Filter 282 allows you to get an idea of the appearance of your image under these 283 conditions. 284 </para> 285 <tip> 286 <para> 287 In case you want not only to change the gamma of the current display, 288 but the change the gamma within the image itself, you can find a 289 description in <xref linkend="gimp-tool-levels"/>. 290 </para> 291 </tip> 292 </sect3> 293 294 <sect3 id="gimp-contrast-dialog"> 295 <title>Contrast</title> 296 <indexterm> 297 <primary>Contrast</primary> 298 </indexterm> 299 <para> 300 <figure> 301 <title>The <quote>Contrast</quote> dialog</title> 302 <mediaobject> 303 <imageobject> 304 <imagedata format="PNG" 305 fileref="images/menus/view/display-filters/contrast.png"/> 306 </imageobject> 307 </mediaobject> 308 </figure> 309 </para> 310 <para> 311 Here, we are back in the medical domain. 312 <quote>Contrast Sensitivity</quote> 313 is the capacity of the visual system to distinguish slight differences 314 in contrast. Some people with cataracts (which means that the lens has 315 opaque crystals that scatter light over the retina) or retinal disease 316 (for instance, due to diabetes, which destroys the rods and cones) have 317 a deficiency in sensitivity to contrast: for example, they would have 318 difficulties distinguishing spots on a dress. 319 </para> 320 <para> 321 If you are interested in this subject, you can browse the Web for 322 <quote>contrast sensitivity</quote>. 323 </para> 324 325 <sect4> 326 <title>Options</title> 327 <variablelist> 328 <varlistentry> 329 <term>Contrast Cycles</term> 330 <listitem> 331 <para> 332 With the <quote>Contrast</quote> 333 Filter, you can see the image as if you were suffering from 334 cataracts. You may have to increase the contrast of the image so 335 that your grandmother can see it well. In most cases, only very 336 low values of the <guilabel>Contrast Cycles</guilabel> 337 parameter are of interest. Higher values create a side-effect 338 which doesn't interest us here: if you increase the luminosity 339 value above 255, the complementary color appears. 340 </para> 341 </listitem> 342 </varlistentry> 343 </variablelist> 344 </sect4> 345 </sect3> 346 347 <sect3 id="gimp-display-filter-clip-warning"> 348 <title>Clip Warning</title> 349 <indexterm> 350 <primary>Clip Warning</primary> 351 </indexterm> 352 <figure> 353 <title>The <quote>Clip Warning</quote> dialog</title> 354 <mediaobject> 355 <imageobject> 356 <imagedata format="PNG" 357 fileref="images/menus/view/display-filters/clip-warning.png"/> 358 </imageobject> 359 </mediaobject> 360 </figure> 361 <para> 362 This filter allows to visualize underexposed and overexposed areas of 363 a photo with user-configurable colors. For now, it’s mostly geared 364 towards images where colors are stored with floating point precision. 365 You will mostly benefit from this, if you work on 16-/32-bit per channel 366 float images such as EXR and TIFF. 367 </para> 368 369 <sect4> 370 <title>Options</title> 371 <variablelist> 372 <varlistentry> 373 <term>Show shadows</term> 374 <listitem> 375 <para> 376 Enable visualization for underexposed pixels (less than 0 in 377 32-bit float mode). 378 </para> 379 </listitem> 380 </varlistentry> 381 <varlistentry> 382 <term>Shadows color</term> 383 <listitem> 384 <para> 385 User-configurable color that will be used to fill underexposed 386 pixels. 387 </para> 388 </listitem> 389 </varlistentry> 390 <varlistentry> 391 <term>Show highlights</term> 392 <listitem> 393 <para> 394 Enable visualization for overexposed pixels (more than 1 in 395 32-bit float mode). 396 </para> 397 </listitem> 398 </varlistentry> 399 <varlistentry> 400 <term>Highlights color</term> 401 <listitem> 402 <para> 403 User-configurable color that will be used to fill overexposed 404 pixels. 405 </para> 406 </listitem> 407 </varlistentry> 408 <varlistentry> 409 <term>Show bogus</term> 410 <listitem> 411 <para> 412 Enable visualization for not-a-number (NaN) pixels, only visible 413 when there is a division by zero error and suchlike. 414 </para> 415 </listitem> 416 </varlistentry> 417 <varlistentry> 418 <term>Bogus color</term> 419 <listitem> 420 <para> 421 User-configurable color that will be used to fill NaN pixels. 422 </para> 423 </listitem> 424 </varlistentry> 425 <varlistentry> 426 <term>Include alpha component</term> 427 <listitem> 428 <para> 429 When enabled, include the alpha component in the warning. 430 </para> 431 </listitem> 432 </varlistentry> 433 <varlistentry> 434 <term>Include transparent pixels</term> 435 <listitem> 436 <para> 437 When enabled, include fully transparent pixels in the warning. 438 </para> 439 </listitem> 440 </varlistentry> 441 </variablelist> 442 </sect4> 443 </sect3> 444</sect2> 445