Krita Source Code Documentation
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IccColorProfile::Private Struct Reference

Classes

struct  ProfileInfo
 
struct  Shared
 

Public Types

using LazyProfileInfo = KisLazyStorage<KisLazyValueWrapper<ProfileInfo>, std::function<ProfileInfo()>>
 

Public Member Functions

ProfileInfo calculateFloatUIMinMax () const
 
 Private ()
 

Public Attributes

QSharedPointer< Sharedshared
 

Detailed Description

Definition at line 65 of file IccColorProfile.cpp.

Member Typedef Documentation

◆ LazyProfileInfo

Constructor & Destructor Documentation

◆ Private()

IccColorProfile::Private::Private ( )
inline

Definition at line 84 of file IccColorProfile.cpp.

Member Function Documentation

◆ calculateFloatUIMinMax()

IccColorProfile::Private::ProfileInfo IccColorProfile::Private::calculateFloatUIMinMax ( ) const

Definition at line 478 of file IccColorProfile.cpp.

479{
480 Private::ProfileInfo info;
482
483 cmsHPROFILE cprofile = shared->lcmsProfile->lcmsProfile();
484 Q_ASSERT(cprofile);
485
486 cmsColorSpaceSignature color_space_sig = cmsGetColorSpace(cprofile);
487 unsigned int num_channels = cmsChannelsOf(color_space_sig);
488 unsigned int color_space_mask = _cmsLCMScolorSpace(color_space_sig);
489
490 Q_ASSERT(num_channels >= 1 && num_channels <= 4); // num_channels==1 is for grayscale, we need to handle it
491 Q_ASSERT(color_space_mask);
492
493 // to try to find the max range of float/doubles for this profile,
494 // pass in min/max int and make the profile convert that
495 // this is far from perfect, we need a better way, if possible to get the "bounds" of a profile
496
497 uint16_t in_min_pixel[4] = {0, 0, 0, 0};
498 uint16_t in_max_pixel[4] = {0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF};
499 qreal out_min_pixel[4] = {0, 0, 0, 0};
500 qreal out_max_pixel[4] = {0, 0, 0, 0};
501
502 cmsHTRANSFORM trans = cmsCreateTransform(
503 cprofile,
504 (COLORSPACE_SH(color_space_mask) | CHANNELS_SH(num_channels) | BYTES_SH(2)),
505 cprofile,
506 (COLORSPACE_SH(color_space_mask) | FLOAT_SH(1) | CHANNELS_SH(num_channels) | BYTES_SH(0)), //NOTE THAT 'BYTES' FIELD IS SET TO ZERO ON DLB because 8 bytes overflows the bitfield
507 INTENT_ABSOLUTE_COLORIMETRIC, 0); // does the intent matter in this case?
508 // absolute colorimetric gives bigger bounds with cmyk's Chemical Proof
509
510 if (trans) {
511 cmsDoTransform(trans, in_min_pixel, out_min_pixel, 1);
512 cmsDoTransform(trans, in_max_pixel, out_max_pixel, 1);
513 cmsDeleteTransform(trans);
514 }//else, we'll just default to [0..1] below
515
516 // Some (calibration) profiles may have a weird RGB->XYZ transformation matrix,
517 // which is not invertible. Therefore, such profile cannot be used as
518 // a workspace color profile and we should convert the image to sRGB
519 // right on image loading
520
521 // LCMS doesn't have a separate method for checking if conversion matrix
522 // is invertible, therefore we just try to create a simple transformation,
523 // where the profile is both, input and output. If the transformation
524 // is created successfully, then this profile is probably suitable for
525 // usage as a working color space.
526
527 info.canCreateCyclicTransform = bool(trans);
528
529 ret.resize(num_channels);
530 for (unsigned int i = 0; i < num_channels; ++i) {
531 if (color_space_sig == cmsSigYCbCrData) {
532 // Although YCbCr profiles are essentially LUT-based
533 // (due to the inability of ICC to represent multiple successive
534 // matrix transforms except with BtoD0 tags in V4),
535 // YCbCr is intended to be a roundtrip transform to the
536 // corresponding RGB transform (BT.601, BT.709).
537 // Force enable the full range of values.
538 ret[i].minVal = 0;
539 ret[i].maxVal = 1;
540 } else if (out_min_pixel[i] < out_max_pixel[i]) {
541 ret[i].minVal = out_min_pixel[i];
542 ret[i].maxVal = out_max_pixel[i];
543 } else {
544 // apparently we can't even guarantee that converted_to_double(0x0000) < converted_to_double(0xFFFF)
545 // assume [0..1] in such cases
546 // we need to find a really solid way of determining the bounds of a profile, if possible
547 ret[i].minVal = 0;
548 ret[i].maxVal = 1;
549 }
550 }
551
552 return info;
553}
#define INTENT_ABSOLUTE_COLORIMETRIC
Definition kis_global.h:106

References KoColorProfile::info, INTENT_ABSOLUTE_COLORIMETRIC, and shared.

Member Data Documentation

◆ shared

QSharedPointer<Shared> IccColorProfile::Private::shared

Definition at line 88 of file IccColorProfile.cpp.


The documentation for this struct was generated from the following file: