347:
249:
273:
285:
373:
261:
385:
397:
361:
22:
531:
Since the brain does not necessarily perceive distinctions in each channel to the same degree as in other channels, it is possible that differing the number of bits allocated to each channel will result in more optimal storage; in particular, for RGB images, compressing the blue channel the most and
236:
If the RGB image is 24-bit (the industry standard as of 2005), each channel has 8 bits, for red, green, and blue—in other words, the image is composed of three images (one for each channel), where each image can store discrete pixels with conventional brightness intensities between 0 and 255. If the
330:
A 32-bit CMYK image (the industry standard as of 2005) is made of four 8-bit channels, one for cyan, one for magenta, one for yellow, and one for key color (typically is black). 64-bit storage for CMYK images (16-bit per channel) is not common, since CMYK is usually device-dependent, whereas RGB is
168:
In the digital realm, there can be any number of conventional primary colors making up an image; a channel in this case is extended to be the grayscale image based on any such conventional primary color. By extension, a channel is any grayscale image of the same dimension as and associated with the
518:
In digitizing images, the color channels are converted to numbers. Since images contain thousands of pixels, each with multiple channels, channels are usually encoded in as few bits as possible. Typical values are 8 bits per channel or 16 bits per channel. Indexed color effectively gets rid of
339:
As of 2011, the 32-bit CMYK image will not be displayed by some major browsers. The RGB image from above is substituted in its place with the link below it. Try saving the link to disk and opening it in another program if it will not display in your
428:, stores color information in three channels, just like RGB, but one channel is devoted to brightness (value), and the other two convey colour information. The value channel is similar to (but not exactly the same as) the CMYK black channel, or its
458:
stores transparency information—the higher the value, the more opaque that pixel is. No camera or scanner measures transparency, although physical objects certainly can possess transparency, but the alpha channel is extremely useful for
183:, which refers to a table where three color components are stored. However, regardless of how a specific format stores the images, discrete color channels can always be determined, as long as a final color image can be rendered.
295:
Notice how the grey trees have similar brightness in all channels, the red dress is much brighter in the red channel than in the other two, and how the green part of the picture is shown much brighter in the green channel.
311:
of the RGB colorspace, originated in broadcasting. The Y channel correlates approximately with perceived intensity, whilst the U and V channels provide colour information.
175:
is a conventional term used to refer to a certain component of an image. In reality, any image format can use any algorithm internally to store images. For instance,
469:
technology involves filming actors in front of a primary color background, then setting that color to transparent, and compositing it with a background.
352:
39:
272:
237:
RGB image is 48-bit (very high color-depth), each channel has 16-bit per pixel color, that is 16-bit red, green, and blue for each per pixel.
284:
260:
346:
105:
86:
579:
58:
248:
65:
43:
396:
145:
137:
image of the same size as a color image, made of just one of these primary colors. For instance, an image from a standard
618:
372:
157:
72:
384:
176:
613:
54:
32:
544:
477:
422:
360:
436:
429:
308:
323:
image has four channels: cyan, magenta, yellow, and key (black). CMYK is the standard for print, where
497:
191:
79:
536:
221:
has three channels: red, green, and blue. RGB channels roughly follow the color receptors in the
500:, multiple channels are used for additional control over material rendering; e.g., controlling
439:
324:
320:
226:
187:
552:
415:
198:
imaging. In that context, each channel corresponds to a range of wavelengths and contains
481:
138:
607:
455:
230:
199:
195:
126:
488:
so that they appear to have an arbitrary shape even on a non-uniform background.
141:
will have a red, green and blue channel. A grayscale image has just one channel.
513:
501:
460:
425:
206:
21:
548:
466:
402:
222:
218:
134:
532:
the red channel the least may be better than giving equal space to each.
485:
559:
587:
519:
channels altogether to get, for instance, 3 channels into 8 bits (
122:
118:
180:
202:
information. The channels can have multiple widths and ranges.
540:
520:
473:
419:
304:
15:
444:
loss of color information is less noticeable to the human eye
209:) exist, and have respective strengths and weaknesses.
179:
images actually refer to the color in each pixel by an
535:
Among other techniques, lossy video compression uses
331:
the generic standard for device-independent storage.
562:
stores red and blue in 5 bits, and green in 6 bits.
46:. Unsourced material may be challenged and removed.
186:The concept of channels is extended beyond the
8:
443:
539:to reduce the bit depth in color channels (
278:The green channel, displayed as grayscale
125:, and pixels are made of combinations of
106:Learn how and when to remove this message
480:image formats use alpha channels on the
290:The blue channel, displayed as grayscale
571:
342:
266:The red channel, displayed as grayscale
244:
152:. Another closely related concept is
7:
148:, channels are often referred to as
44:adding citations to reliable sources
129:represented by a series of code. A
14:
395:
383:
371:
359:
345:
283:
271:
259:
247:
20:
584:ArcSDE SDK C and Java APIs 10.0
31:needs additional citations for
146:geographic information systems
1:
205:Three main channel types (or
158:convolutional neural networks
435:HSV is especially useful in
55:"Channel" digital image
121:digital images are made of
635:
511:
338:
463:digital images together.
353:Example 32-bit CMYK image
527:Optimized channel sizes
133:in this context is the
551:information (value in
547:), while keeping all
309:affine transformation
498:3D computer graphics
325:subtractive coloring
156:, which are used in
40:improve this article
619:Digital photography
484:to merge images on
537:chroma subsampling
254:A 24-bit RGB image
225:, and are used in
614:Computer graphics
440:video compression
335:CMYK color sample
227:computer displays
116:
115:
108:
90:
626:
598:
597:
595:
594:
576:
399:
387:
375:
363:
349:
287:
275:
263:
251:
241:RGB color sample
188:visible spectrum
169:original image.
111:
104:
100:
97:
91:
89:
48:
24:
16:
634:
633:
629:
628:
627:
625:
624:
623:
604:
603:
602:
601:
592:
590:
578:
577:
573:
568:
529:
516:
510:
494:
452:
413:
406:
400:
391:
388:
379:
378:Magenta channel
376:
367:
364:
355:
350:
341:
337:
317:
302:
291:
288:
279:
276:
267:
264:
255:
252:
243:
215:
166:
112:
101:
95:
92:
49:
47:
37:
25:
12:
11:
5:
632:
630:
622:
621:
616:
606:
605:
600:
599:
580:"Raster Bands"
570:
569:
567:
564:
528:
525:
523:) or 16 bits.
512:Main article:
509:
506:
493:
492:Other channels
490:
482:World Wide Web
451:
448:
412:
409:
408:
407:
401:
394:
392:
390:Yellow channel
389:
382:
380:
377:
370:
368:
365:
358:
356:
351:
344:
336:
333:
316:
313:
307:images are an
301:
298:
293:
292:
289:
282:
280:
277:
270:
268:
265:
258:
256:
253:
246:
242:
239:
231:image scanners
214:
211:
165:
162:
139:digital camera
127:primary colors
114:
113:
28:
26:
19:
13:
10:
9:
6:
4:
3:
2:
631:
620:
617:
615:
612:
611:
609:
589:
585:
581:
575:
572:
565:
563:
561:
556:
554:
550:
546:
542:
538:
533:
526:
524:
522:
515:
507:
505:
503:
499:
491:
489:
487:
483:
479:
475:
470:
468:
464:
462:
457:
456:alpha channel
450:Alpha channel
449:
447:
445:
441:
438:
433:
431:
427:
424:
421:
417:
410:
404:
398:
393:
386:
381:
374:
369:
362:
357:
354:
348:
343:
334:
332:
328:
326:
322:
314:
312:
310:
306:
299:
297:
286:
281:
274:
269:
262:
257:
250:
245:
240:
238:
234:
232:
228:
224:
220:
212:
210:
208:
203:
201:
200:spectroscopic
197:
196:hyperspectral
193:
192:multispectral
189:
184:
182:
178:
174:
170:
163:
161:
159:
155:
151:
147:
142:
140:
136:
132:
128:
124:
120:
110:
107:
99:
96:December 2018
88:
85:
81:
78:
74:
71:
67:
64:
60:
57: –
56:
52:
51:Find sources:
45:
41:
35:
34:
29:This article
27:
23:
18:
17:
591:. Retrieved
583:
574:
557:
534:
530:
517:
495:
471:
465:
453:
434:
414:
366:Cyan channel
329:
318:
303:
294:
235:
216:
207:color models
204:
185:
181:index number
172:
171:
167:
154:feature maps
153:
150:raster bands
149:
143:
130:
117:
102:
93:
83:
76:
69:
62:
50:
38:Please help
33:verification
30:
514:Color depth
504:and so on.
502:specularity
461:compositing
403:Key (black)
608:Categories
593:2020-07-28
566:References
549:brightness
545:saturation
467:Bluescreen
423:saturation
213:RGB images
66:newspapers
508:Bit depth
486:web pages
327:is used.
223:human eye
219:RGB image
135:grayscale
442:, where
430:negative
340:browser.
164:Overview
560:HiColor
558:16-bit
405:channel
173:Channel
131:channel
80:scholar
588:ArcGIS
123:pixels
82:
75:
68:
61:
53:
437:lossy
426:value
418:, or
119:Color
87:JSTOR
73:books
543:and
476:and
472:The
454:The
321:CMYK
315:CMYK
229:and
194:and
59:news
555:).
553:HSV
541:hue
521:GIF
496:In
478:PNG
474:GIF
420:hue
416:HSV
411:HSV
305:YUV
300:YUV
217:An
190:in
177:GIF
144:In
42:by
610::
586:.
582:.
446:.
432:.
319:A
233:.
160:.
596:.
109:)
103:(
98:)
94:(
84:·
77:·
70:·
63:·
36:.
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
