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<html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>GimpColorSpace</title><meta name="generator" content="DocBook XSL Stylesheets V1.66.1"><link rel="start" href="index.html" title="GIMP Color Library Reference Manual"><link rel="up" href="libgimpcolor.html" title="Part�I.�GIMP Color Library"><link rel="prev" href="libgimpcolor-GimpCMYK.html" title="GimpCMYK"><link rel="next" href="libgimpcolor-GimpAdaptiveSupersample.html" title="GimpAdaptiveSupersample"><meta name="generator" content="GTK-Doc V1.2 (XML mode)"><style type="text/css">

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</style></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><table class="navigation" width="100%" summary="Navigation header" cellpadding="2" cellspacing="2"><tr valign="middle"><td><a accesskey="p" href="libgimpcolor-GimpCMYK.html"><img src="left.png" width="24" height="24" border="0" alt="Prev"></a></td><td><a accesskey="u" href="libgimpcolor.html"><img src="up.png" width="24" height="24" border="0" alt="Up"></a></td><td><a accesskey="h" href="index.html"><img src="home.png" width="24" height="24" border="0" alt="Home"></a></td><th width="100%" align="center">GIMP Color Library Reference Manual</th><td><a accesskey="n" href="libgimpcolor-GimpAdaptiveSupersample.html"><img src="right.png" width="24" height="24" border="0" alt="Next"></a></td></tr></table><div class="refentry" lang="en"><a name="libgimpcolor-GimpColorSpace"></a><div class="titlepage"></div><div class="refnamediv"><h2><span class="refentrytitle">GimpColorSpace</span></h2><p>GimpColorSpace — Utility functions which convert colors between different color models.</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><pre class="synopsis">

struct <a href="libgimpcolor-GimpColorSpace.html#GimpHSL">GimpHSL</a>;

void <a href="libgimpcolor-GimpColorSpace.html#gimp-rgb-to-hsv">gimp_rgb_to_hsv</a> (const <a href="libgimpcolor-GimpRGB.html#GimpRGB">GimpRGB</a> *rgb,

<a href="libgimpcolor-GimpHSV.html#GimpHSV">GimpHSV</a> *hsv);

void <a href="libgimpcolor-GimpColorSpace.html#gimp-rgb-to-hsl">gimp_rgb_to_hsl</a> (const <a href="libgimpcolor-GimpRGB.html#GimpRGB">GimpRGB</a> *rgb,

<a href="libgimpcolor-GimpColorSpace.html#GimpHSL">GimpHSL</a> *hsl);

void <a href="libgimpcolor-GimpColorSpace.html#gimp-rgb-to-cmyk">gimp_rgb_to_cmyk</a> (const <a href="libgimpcolor-GimpRGB.html#GimpRGB">GimpRGB</a> *rgb,

href="../glib/glib-Basic-Types.html#gdouble"

>gdouble</a> pullout,

<a href="libgimpcolor-GimpCMYK.html#GimpCMYK">GimpCMYK</a> *cmyk);

void <a href="libgimpcolor-GimpColorSpace.html#gimp-hsv-to-rgb">gimp_hsv_to_rgb</a> (const <a href="libgimpcolor-GimpHSV.html#GimpHSV">GimpHSV</a> *hsv,

<a href="libgimpcolor-GimpRGB.html#GimpRGB">GimpRGB</a> *rgb);

void <a href="libgimpcolor-GimpColorSpace.html#gimp-hsl-to-rgb">gimp_hsl_to_rgb</a> (const <a href="libgimpcolor-GimpColorSpace.html#GimpHSL">GimpHSL</a> *hsl,

<a href="libgimpcolor-GimpRGB.html#GimpRGB">GimpRGB</a> *rgb);

void <a href="libgimpcolor-GimpColorSpace.html#gimp-cmyk-to-rgb">gimp_cmyk_to_rgb</a> (const <a href="libgimpcolor-GimpCMYK.html#GimpCMYK">GimpCMYK</a> *cmyk,

<a href="libgimpcolor-GimpRGB.html#GimpRGB">GimpRGB</a> *rgb);

void <a href="libgimpcolor-GimpColorSpace.html#gimp-rgb-to-hwb">gimp_rgb_to_hwb</a> (const <a href="libgimpcolor-GimpRGB.html#GimpRGB">GimpRGB</a> *rgb,

href="../glib/glib-Basic-Types.html#gdouble"

>gdouble</a> *hue,

href="../glib/glib-Basic-Types.html#gdouble"

>gdouble</a> *whiteness,

href="../glib/glib-Basic-Types.html#gdouble"

>gdouble</a> *blackness);

void <a href="libgimpcolor-GimpColorSpace.html#gimp-hwb-to-rgb">gimp_hwb_to_rgb</a> (<a

href="../glib/glib-Basic-Types.html#gdouble"

>gdouble</a> hue,

href="../glib/glib-Basic-Types.html#gdouble"

>gdouble</a> whiteness,

href="../glib/glib-Basic-Types.html#gdouble"

>gdouble</a> blackness,

<a href="libgimpcolor-GimpRGB.html#GimpRGB">GimpRGB</a> *rgb);

void <a href="libgimpcolor-GimpColorSpace.html#gimp-rgb-to-hsv-int">gimp_rgb_to_hsv_int</a> (<a

href="../glib/glib-Basic-Types.html#gint"

>gint</a> *red,

href="../glib/glib-Basic-Types.html#gint"

>gint</a> *green,

href="../glib/glib-Basic-Types.html#gint"

>gint</a> *blue);

void <a href="libgimpcolor-GimpColorSpace.html#gimp-hsv-to-rgb-int">gimp_hsv_to_rgb_int</a> (<a

href="../glib/glib-Basic-Types.html#gint"

>gint</a> *hue,

href="../glib/glib-Basic-Types.html#gint"

>gint</a> *saturation,

href="../glib/glib-Basic-Types.html#gint"

>gint</a> *value);

void <a href="libgimpcolor-GimpColorSpace.html#gimp-rgb-to-hsl-int">gimp_rgb_to_hsl_int</a> (<a

href="../glib/glib-Basic-Types.html#gint"

>gint</a> *red,

href="../glib/glib-Basic-Types.html#gint"

>gint</a> *green,

href="../glib/glib-Basic-Types.html#gint"

>gint</a> *blue);

void <a href="libgimpcolor-GimpColorSpace.html#gimp-rgb-to-cmyk-int">gimp_rgb_to_cmyk_int</a> (<a

href="../glib/glib-Basic-Types.html#gint"

100

>gint</a> *red,

101

102

href="../glib/glib-Basic-Types.html#gint"

103

>gint</a> *green,

104

105

href="../glib/glib-Basic-Types.html#gint"

106

>gint</a> *blue,

107

108

href="../glib/glib-Basic-Types.html#gint"

109

>gint</a> *pullout);

110

void <a href="libgimpcolor-GimpColorSpace.html#gimp-cmyk-to-rgb-int">gimp_cmyk_to_rgb_int</a> (<a

111

href="../glib/glib-Basic-Types.html#gint"

112

>gint</a> *cyan,

113

114

href="../glib/glib-Basic-Types.html#gint"

115

>gint</a> *magenta,

116

117

href="../glib/glib-Basic-Types.html#gint"

118

>gint</a> *yellow,

119

120

href="../glib/glib-Basic-Types.html#gint"

121

>gint</a> *black);

122

123

href="../glib/glib-Basic-Types.html#gint"

124

>gint</a> <a href="libgimpcolor-GimpColorSpace.html#gimp-rgb-to-l-int">gimp_rgb_to_l_int</a> (<a

125

href="../glib/glib-Basic-Types.html#gint"

126

>gint</a> red,

127

128

href="../glib/glib-Basic-Types.html#gint"

129

>gint</a> green,

130

131

href="../glib/glib-Basic-Types.html#gint"

132

>gint</a> blue);

133

void <a href="libgimpcolor-GimpColorSpace.html#gimp-hsl-to-rgb-int">gimp_hsl_to_rgb_int</a> (<a

134

href="../glib/glib-Basic-Types.html#gint"

135

>gint</a> *hue,

136

137

href="../glib/glib-Basic-Types.html#gint"

138

>gint</a> *saturation,

139

140

href="../glib/glib-Basic-Types.html#gint"

141

>gint</a> *lightness);

142

void <a href="libgimpcolor-GimpColorSpace.html#gimp-rgb-to-hsv4">gimp_rgb_to_hsv4</a> (<a

143

href="../glib/glib-Basic-Types.html#guchar"

144

>guchar</a> *rgb,

145

146

href="../glib/glib-Basic-Types.html#gdouble"

147

>gdouble</a> *hue,

148

149

href="../glib/glib-Basic-Types.html#gdouble"

150

>gdouble</a> *saturation,

151

152

href="../glib/glib-Basic-Types.html#gdouble"

153

>gdouble</a> *value);

154

void <a href="libgimpcolor-GimpColorSpace.html#gimp-hsv-to-rgb4">gimp_hsv_to_rgb4</a> (<a

155

href="../glib/glib-Basic-Types.html#guchar"

156

>guchar</a> *rgb,

157

158

href="../glib/glib-Basic-Types.html#gdouble"

159

>gdouble</a> hue,

160

161

href="../glib/glib-Basic-Types.html#gdouble"

162

>gdouble</a> saturation,

163

164

href="../glib/glib-Basic-Types.html#gdouble"

165

>gdouble</a> value);

166

</pre></div><div class="refsect1" lang="en"><a name="id2582420"></a><h2>Description</h2><p>

167

When programming pixel data manipulation functions you will often use

168

algorithms operating on a color model different from the one GIMP

169

uses. This file provides utility functions to convert colors between

170

different color spaces.

171

</p></div><div class="refsect1" lang="en"><a name="id2582434"></a><h2>Details</h2><div class="refsect2" lang="en"><a name="id2582439"></a><h3><a name="GimpHSL"></a>struct GimpHSL</h3><a class="indexterm" name="id2582448"></a><pre class="programlisting">struct GimpHSL {

172

173

gdouble h, s, l, a;

174

};

175

</pre><p>

176

177

</p></div><hr><div class="refsect2" lang="en"><a name="id2582457"></a><h3><a name="gimp-rgb-to-hsv"></a>gimp_rgb_to_hsv ()</h3><a class="indexterm" name="id2582466"></a><pre class="programlisting">void gimp_rgb_to_hsv (const <a href="libgimpcolor-GimpRGB.html#GimpRGB">GimpRGB</a> *rgb,

178

<a href="libgimpcolor-GimpHSV.html#GimpHSV">GimpHSV</a> *hsv);</pre><p>

179

Does a conversion from RGB to HSV (Hue, Saturation,

180

Value) colorspace.</p><p>

181

182

</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>rgb</tt></i>�:</span></td><td> A color value in the RGB colorspace

183

</td></tr><tr><td><span class="term"><i class="parameter"><tt>hsv</tt></i>�:</span></td><td> The value converted to the HSV colorspace

184

</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id2529232"></a><h3><a name="gimp-rgb-to-hsl"></a>gimp_rgb_to_hsl ()</h3><a class="indexterm" name="id2529241"></a><pre class="programlisting">void gimp_rgb_to_hsl (const <a href="libgimpcolor-GimpRGB.html#GimpRGB">GimpRGB</a> *rgb,

185

<a href="libgimpcolor-GimpColorSpace.html#GimpHSL">GimpHSL</a> *hsl);</pre><p>

186

Convert an RGB color value to a HSL (Hue, Saturation, Lightness)

187

color value.</p><p>

188

189

190

</td></tr><tr><td><span class="term"><i class="parameter"><tt>hsl</tt></i>�:</span></td><td> The value converted to HSL

191

</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id2529297"></a><h3><a name="gimp-rgb-to-cmyk"></a>gimp_rgb_to_cmyk ()</h3><a class="indexterm" name="id2529305"></a><pre class="programlisting">void gimp_rgb_to_cmyk (const <a href="libgimpcolor-GimpRGB.html#GimpRGB">GimpRGB</a> *rgb,

192

193

href="../glib/glib-Basic-Types.html#gdouble"

194

>gdouble</a> pullout,

195

<a href="libgimpcolor-GimpCMYK.html#GimpCMYK">GimpCMYK</a> *cmyk);</pre><p>

196

Does a naive conversion from RGB to CMYK colorspace. A simple

197

formula that doesn't take any color-profiles into account is used.

198

The amount of black pullout how can be controlled via the <i class="parameter"><tt>pullout</tt></i>

199

parameter. A <i class="parameter"><tt>pullout</tt></i> value of 0 makes this a conversion to CMY.

200

A value of 1 causes the maximum amount of black to be pulled out.</p><p>

201

202

203

</td></tr><tr><td><span class="term"><i class="parameter"><tt>pullout</tt></i>�:</span></td><td> A scaling value (0-1) indicating how much black should be

204

pulled out

205

</td></tr><tr><td><span class="term"><i class="parameter"><tt>cmyk</tt></i>�:</span></td><td> The input value naively converted to the CMYK colorspace

206

</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id2529391"></a><h3><a name="gimp-hsv-to-rgb"></a>gimp_hsv_to_rgb ()</h3><a class="indexterm" name="id2529400"></a><pre class="programlisting">void gimp_hsv_to_rgb (const <a href="libgimpcolor-GimpHSV.html#GimpHSV">GimpHSV</a> *hsv,

207

<a href="libgimpcolor-GimpRGB.html#GimpRGB">GimpRGB</a> *rgb);</pre><p>

208

Converts a color value from HSV to RGB colorspace</p><p>

209

210

</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>hsv</tt></i>�:</span></td><td> A color value in the HSV colorspace

211

</td></tr><tr><td><span class="term"><i class="parameter"><tt>rgb</tt></i>�:</span></td><td> The returned RGB value.

212

</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id2529455"></a><h3><a name="gimp-hsl-to-rgb"></a>gimp_hsl_to_rgb ()</h3><a class="indexterm" name="id2529464"></a><pre class="programlisting">void gimp_hsl_to_rgb (const <a href="libgimpcolor-GimpColorSpace.html#GimpHSL">GimpHSL</a> *hsl,

213

<a href="libgimpcolor-GimpRGB.html#GimpRGB">GimpRGB</a> *rgb);</pre><p>

214

Convert a HSL color value to an RGB color value.</p><p>

215

216

</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>hsl</tt></i>�:</span></td><td> A color value in the HSL colorspace

217

</td></tr><tr><td><span class="term"><i class="parameter"><tt>rgb</tt></i>�:</span></td><td> The value converted to a value in the RGB colorspace

218

</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id2587457"></a><h3><a name="gimp-cmyk-to-rgb"></a>gimp_cmyk_to_rgb ()</h3><a class="indexterm" name="id2587466"></a><pre class="programlisting">void gimp_cmyk_to_rgb (const <a href="libgimpcolor-GimpCMYK.html#GimpCMYK">GimpCMYK</a> *cmyk,

219

<a href="libgimpcolor-GimpRGB.html#GimpRGB">GimpRGB</a> *rgb);</pre><p>

220

Does a simple transformation from the CMYK colorspace to the RGB

221

colorspace, without taking color profiles into account.</p><p>

222

223

</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>cmyk</tt></i>�:</span></td><td> A color value in the CMYK colorspace

224

</td></tr><tr><td><span class="term"><i class="parameter"><tt>rgb</tt></i>�:</span></td><td> The value converted to the RGB colorspace

225

</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id2587524"></a><h3><a name="gimp-rgb-to-hwb"></a>gimp_rgb_to_hwb ()</h3><a class="indexterm" name="id2587532"></a><pre class="programlisting">void gimp_rgb_to_hwb (const <a href="libgimpcolor-GimpRGB.html#GimpRGB">GimpRGB</a> *rgb,

226

227

href="../glib/glib-Basic-Types.html#gdouble"

228

>gdouble</a> *hue,

229

230

href="../glib/glib-Basic-Types.html#gdouble"

231

>gdouble</a> *whiteness,

232

233

href="../glib/glib-Basic-Types.html#gdouble"

234

>gdouble</a> *blackness);</pre><p>

235

Theoretically, hue 0 (pure red) is identical to hue 6 in these transforms.

236

Pure red always maps to 6 in this implementation. Therefore UNDEFINED can

237

be defined as 0 in situations where only unsigned numbers are desired.

238

</p><p>

239

RGB are each on [0, 1]. Whiteness and Blackness are returned in the

240

range [0, 1] and H is returned in the range [0, 6]. If W == 1 - B, H is

241

undefined.</p><p>

242

243

244

</td></tr><tr><td><span class="term"><i class="parameter"><tt>hue</tt></i>�:</span></td><td> The hue value of the above color, in the range 0 to 6

245

</td></tr><tr><td><span class="term"><i class="parameter"><tt>whiteness</tt></i>�:</span></td><td> The whiteness value of the above color, in the range 0 to 1

246

</td></tr><tr><td><span class="term"><i class="parameter"><tt>blackness</tt></i>�:</span></td><td> The blackness value of the above color, in the range 0 to 1

247

</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id2587635"></a><h3><a name="gimp-hwb-to-rgb"></a>gimp_hwb_to_rgb ()</h3><a class="indexterm" name="id2587644"></a><pre class="programlisting">void gimp_hwb_to_rgb (<a

248

href="../glib/glib-Basic-Types.html#gdouble"

249

>gdouble</a> hue,

250

251

href="../glib/glib-Basic-Types.html#gdouble"

252

>gdouble</a> whiteness,

253

254

href="../glib/glib-Basic-Types.html#gdouble"

255

>gdouble</a> blackness,

256

<a href="libgimpcolor-GimpRGB.html#GimpRGB">GimpRGB</a> *rgb);</pre><p>

257

H is defined in the range [0, 6] or UNDEFINED, B and W are both in the

258

range [0, 1]. The returned RGB values are all in the range [0, 1].</p><p>

259

260

</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>hue</tt></i>�:</span></td><td> A hue value, in the range 0 to 6

261

</td></tr><tr><td><span class="term"><i class="parameter"><tt>whiteness</tt></i>�:</span></td><td> A whiteness value, in the range 0 to 1

262

</td></tr><tr><td><span class="term"><i class="parameter"><tt>blackness</tt></i>�:</span></td><td> A blackness value, in the range 0 to 1

263

</td></tr><tr><td><span class="term"><i class="parameter"><tt>rgb</tt></i>�:</span></td><td> The above color converted to the RGB colorspace

264

</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id2587737"></a><h3><a name="gimp-rgb-to-hsv-int"></a>gimp_rgb_to_hsv_int ()</h3><a class="indexterm" name="id2587745"></a><pre class="programlisting">void gimp_rgb_to_hsv_int (<a

265

href="../glib/glib-Basic-Types.html#gint"

266

>gint</a> *red,

267

268

href="../glib/glib-Basic-Types.html#gint"

269

>gint</a> *green,

270

271

href="../glib/glib-Basic-Types.html#gint"

272

>gint</a> *blue);</pre><p>

273

The arguments are pointers to int representing channel values in

274

the RGB colorspace, and the values pointed to are all in the range

275

[0, 255].

276

</p><p>

277

The function changes the arguments to point to the HSV value

278

corresponding, with the returned values in the following

279

ranges: H [0, 360], S [0, 255], V [0, 255].</p><p>

280

281

</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>red</tt></i>�:</span></td><td> The red channel value, returns the Hue channel

282

</td></tr><tr><td><span class="term"><i class="parameter"><tt>green</tt></i>�:</span></td><td> The green channel value, returns the Saturation channel

283

</td></tr><tr><td><span class="term"><i class="parameter"><tt>blue</tt></i>�:</span></td><td> The blue channel value, returns the Value channel

284

</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id2587828"></a><h3><a name="gimp-hsv-to-rgb-int"></a>gimp_hsv_to_rgb_int ()</h3><a class="indexterm" name="id2587837"></a><pre class="programlisting">void gimp_hsv_to_rgb_int (<a

285

href="../glib/glib-Basic-Types.html#gint"

286

>gint</a> *hue,

287

288

href="../glib/glib-Basic-Types.html#gint"

289

>gint</a> *saturation,

290

291

href="../glib/glib-Basic-Types.html#gint"

292

>gint</a> *value);</pre><p>

293

The arguments are pointers to int, with the values pointed to in the

294

following ranges: H [0, 360], S [0, 255], V [0, 255].

295

</p><p>

296

The function changes the arguments to point to the RGB value

297

corresponding, with the returned values all in the range [0, 255].</p><p>

298

299

300

</td></tr><tr><td><span class="term"><i class="parameter"><tt>saturation</tt></i>�:</span></td><td> The saturation channel, returns the green channel

301

</td></tr><tr><td><span class="term"><i class="parameter"><tt>value</tt></i>�:</span></td><td> The value channel, returns the blue channel

302

</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id2587874"></a><h3><a name="gimp-rgb-to-hsl-int"></a>gimp_rgb_to_hsl_int ()</h3><a class="indexterm" name="id2587881"></a><pre class="programlisting">void gimp_rgb_to_hsl_int (<a

303

href="../glib/glib-Basic-Types.html#gint"

304

>gint</a> *red,

305

306

href="../glib/glib-Basic-Types.html#gint"

307

>gint</a> *green,

308

309

href="../glib/glib-Basic-Types.html#gint"

310

>gint</a> *blue);</pre><p>

311

The arguments are pointers to int representing channel values in the

312

RGB colorspace, and the values pointed to are all in the range [0, 255].

313

</p><p>

314

The function changes the arguments to point to the corresponding HLS

315

value with the values pointed to in the following ranges: H [0, 360],

316

L [0, 255], S [0, 255].</p><p>

317

318

319

</td></tr><tr><td><span class="term"><i class="parameter"><tt>green</tt></i>�:</span></td><td> Green channel, returns Lightness channel

320

</td></tr><tr><td><span class="term"><i class="parameter"><tt>blue</tt></i>�:</span></td><td> Blue channel, returns Saturation channel

321

</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id2587956"></a><h3><a name="gimp-rgb-to-cmyk-int"></a>gimp_rgb_to_cmyk_int ()</h3><a class="indexterm" name="id2587964"></a><pre class="programlisting">void gimp_rgb_to_cmyk_int (<a

322

href="../glib/glib-Basic-Types.html#gint"

323

>gint</a> *red,

324

325

href="../glib/glib-Basic-Types.html#gint"

326

>gint</a> *green,

327

328

href="../glib/glib-Basic-Types.html#gint"

329

>gint</a> *blue,

330

331

href="../glib/glib-Basic-Types.html#gint"

332

>gint</a> *pullout);</pre><p>

333

Does a naive conversion from RGB to CMYK colorspace. A simple

334

formula that doesn't take any color-profiles into account is used.

335

The amount of black pullout how can be controlled via the <i class="parameter"><tt>pullout</tt></i>

336

parameter. A <i class="parameter"><tt>pullout</tt></i> value of 0 makes this a conversion to CMY.

337

A value of 100 causes the maximum amount of black to be pulled out.</p><p>

338

339

340

</td></tr><tr><td><span class="term"><i class="parameter"><tt>green</tt></i>�:</span></td><td> the green channel; returns the magenta value (0-255)

341

</td></tr><tr><td><span class="term"><i class="parameter"><tt>blue</tt></i>�:</span></td><td> the blue channel; returns the yellow value (0-255)

342

</td></tr><tr><td><span class="term"><i class="parameter"><tt>pullout</tt></i>�:</span></td><td> the percentage of black to pull out (0-100); returns

343

the black value (0-255)

344

</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id2588062"></a><h3><a name="gimp-cmyk-to-rgb-int"></a>gimp_cmyk_to_rgb_int ()</h3><a class="indexterm" name="id2588070"></a><pre class="programlisting">void gimp_cmyk_to_rgb_int (<a

345

href="../glib/glib-Basic-Types.html#gint"

346

>gint</a> *cyan,

347

348

href="../glib/glib-Basic-Types.html#gint"

349

>gint</a> *magenta,

350

351

href="../glib/glib-Basic-Types.html#gint"

352

>gint</a> *yellow,

353

354

href="../glib/glib-Basic-Types.html#gint"

355

>gint</a> *black);</pre><p>

356

Does a naive conversion from CMYK to RGB colorspace. A simple

357

formula that doesn't take any color-profiles into account is used.</p><p>

358

359

</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>cyan</tt></i>�:</span></td><td> the cyan channel; returns the red value (0-255)

360

</td></tr><tr><td><span class="term"><i class="parameter"><tt>magenta</tt></i>�:</span></td><td> the magenta channel; returns the green value (0-255)

361

</td></tr><tr><td><span class="term"><i class="parameter"><tt>yellow</tt></i>�:</span></td><td> the yellow channel; returns the blue value (0-255)

362

</td></tr><tr><td><span class="term"><i class="parameter"><tt>black</tt></i>�:</span></td><td> the black channel (0-255); doesn't change

363

</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id2588160"></a><h3><a name="gimp-rgb-to-l-int"></a>gimp_rgb_to_l_int ()</h3><a class="indexterm" name="id2588168"></a><pre class="programlisting"><a

364

href="../glib/glib-Basic-Types.html#gint"

365

>gint</a> gimp_rgb_to_l_int (<a

366

href="../glib/glib-Basic-Types.html#gint"

367

>gint</a> red,

368

369

href="../glib/glib-Basic-Types.html#gint"

370

>gint</a> green,

371

372

href="../glib/glib-Basic-Types.html#gint"

373

>gint</a> blue);</pre><p>

374

Calculates the lightness value of an RGB triplet with the formula

375

L = (max(R, G, B) + min (R, G, B)) / 2</p><p>

376

377

</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>red</tt></i>�:</span></td><td> Red channel

378

</td></tr><tr><td><span class="term"><i class="parameter"><tt>green</tt></i>�:</span></td><td> Green channel

379

</td></tr><tr><td><span class="term"><i class="parameter"><tt>blue</tt></i>�:</span></td><td> Blue channel

380

</td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td><td> Luminance vaue corresponding to the input RGB value

381

</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id2588252"></a><h3><a name="gimp-hsl-to-rgb-int"></a>gimp_hsl_to_rgb_int ()</h3><a class="indexterm" name="id2588260"></a><pre class="programlisting">void gimp_hsl_to_rgb_int (<a

382

href="../glib/glib-Basic-Types.html#gint"

383

>gint</a> *hue,

384

385

href="../glib/glib-Basic-Types.html#gint"

386

>gint</a> *saturation,

387

388

href="../glib/glib-Basic-Types.html#gint"

389

>gint</a> *lightness);</pre><p>

390

The arguments are pointers to int, with the values pointed to in the

391

following ranges: H [0, 360], L [0, 255], S [0, 255].

392

</p><p>

393

The function changes the arguments to point to the RGB value

394

corresponding, with the returned values all in the range [0, 255].</p><p>

395

396

397

</td></tr><tr><td><span class="term"><i class="parameter"><tt>saturation</tt></i>�:</span></td><td> Saturation channel, returns Green channel

398

</td></tr><tr><td><span class="term"><i class="parameter"><tt>lightness</tt></i>�:</span></td><td> Lightness channel, returns Blue channel

399

</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id2588339"></a><h3><a name="gimp-rgb-to-hsv4"></a>gimp_rgb_to_hsv4 ()</h3><a class="indexterm" name="id2588347"></a><pre class="programlisting">void gimp_rgb_to_hsv4 (<a

400

href="../glib/glib-Basic-Types.html#guchar"

401

>guchar</a> *rgb,

402

403

href="../glib/glib-Basic-Types.html#gdouble"

404

>gdouble</a> *hue,

405

406

href="../glib/glib-Basic-Types.html#gdouble"

407

>gdouble</a> *saturation,

408

409

href="../glib/glib-Basic-Types.html#gdouble"

410

>gdouble</a> *value);</pre><p>

411

</p><p>

412

413

414

rgb[2] is blue (0..255)

415

</td></tr><tr><td><span class="term"><i class="parameter"><tt>hue</tt></i>�:</span></td><td> Pointer to hue channel (0..1)

416

</td></tr><tr><td><span class="term"><i class="parameter"><tt>saturation</tt></i>�:</span></td><td> Pointer to saturation channel (0..1)

417

</td></tr><tr><td><span class="term"><i class="parameter"><tt>value</tt></i>�:</span></td><td> Pointer to value channel (0..1)

418

</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id2588436"></a><h3><a name="gimp-hsv-to-rgb4"></a>gimp_hsv_to_rgb4 ()</h3><a class="indexterm" name="id2588445"></a><pre class="programlisting">void gimp_hsv_to_rgb4 (<a

419

href="../glib/glib-Basic-Types.html#guchar"

420

>guchar</a> *rgb,

421

422

href="../glib/glib-Basic-Types.html#gdouble"

423

>gdouble</a> hue,

424

425

href="../glib/glib-Basic-Types.html#gdouble"

426

>gdouble</a> saturation,

427

428

href="../glib/glib-Basic-Types.html#gdouble"

429

>gdouble</a> value);</pre><p>

430

</p><p>

431

432

433

rgb[2] is blue (0..255)

434

</td></tr><tr><td><span class="term"><i class="parameter"><tt>hue</tt></i>�:</span></td><td> Hue channel (0..1)

435

</td></tr><tr><td><span class="term"><i class="parameter"><tt>saturation</tt></i>�:</span></td><td> Saturation channel (0..1)

436

</td></tr><tr><td><span class="term"><i class="parameter"><tt>value</tt></i>�:</span></td><td> Value channel (0..1)

437

</td></tr></tbody></table></div></div></div></div><table class="navigation" width="100%" summary="Navigation footer" cellpadding="2" cellspacing="0"><tr valign="middle"><td align="left"><a accesskey="p" href="libgimpcolor-GimpCMYK.html"><b><<�GimpCMYK</b></a></td><td align="right"><a accesskey="n" href="libgimpcolor-GimpAdaptiveSupersample.html"><b>GimpAdaptiveSupersample�>></b></a></td></tr></table></body></html>

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