wilderjds
/
okular
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Add some color modes: Invert Lightness/Luma, Hue Shift

Browse Source
remotes/origin/work/aacid/use_mimes_open_dialog
David Hurka 6 years ago committed by Albert Astals Cid
parent 9694113a96
commit aa6833483e
6 changed files with 351 additions and 21 deletions
Whitespace
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Split View
Diff Options
Show Stats Download Patch File Download Diff File
  1. 5
      conf/dlgaccessibility.cpp
  2. 40
      conf/dlgaccessibilitybase.ui
  3. 5
      conf/okular_core.kcfg
  4. 41
      doc/index.docbook
  5. 260
      ui/pagepainter.cpp
  6. 21
      ui/pagepainter.h

5
conf/dlgaccessibility.cpp
Unescape View File

@ -30,6 +30,11 @@ DlgAccessibility::DlgAccessibility( QWidget * parent )
m_color_pages.append( m_dlg->page_paperColor );
m_color_pages.append( m_dlg->page_darkLight );
m_color_pages.append( m_dlg->page_bw );
m_color_pages.append( m_dlg->page_invertLightness );
m_color_pages.append( m_dlg->page_invertLuma );
m_color_pages.append( m_dlg->page_invertLumaSymmetric );
m_color_pages.append( m_dlg->page_hueShiftPositive );
m_color_pages.append( m_dlg->page_hueShiftNegative );
for ( QWidget *page : qAsConst(m_color_pages) ) {
page->hide();
}

40
conf/dlgaccessibilitybase.ui
Unescape View File

@ -107,6 +107,31 @@
<string>Convert to Black &amp; White</string>
</property>
</item>
<item>
<property name="text" >
<string>Invert Lightness</string>
</property>
</item>
<item>
<property name="text" >
<string>Invert Luma (sRGB Linear)</string>
</property>
</item>
<item>
<property name="text" >
<string>Invert Luma (Symmetric)</string>
</property>
</item>
<item>
<property name="text" >
<string>Shift Hue Positive</string>
</property>
</item>
<item>
<property name="text" >
<string>Shift Hue Negative</string>
</property>
</item>
</widget>
</item>
</layout>
@ -363,6 +388,21 @@
</layout>
</widget>
</item>
<item>
<widget class="QWidget" native="1" name="page_invertLightness" />
</item>
<item>
<widget class="QWidget" native="1" name="page_invertLuma" />
</item>
<item>
<widget class="QWidget" native="1" name="page_invertLumaSymmetric" />
</item>
<item>
<widget class="QWidget" native="1" name="page_hueShiftPositive" />
</item>
<item>
<widget class="QWidget" native="1" name="page_hueShiftNegative" />
</item>
</layout>
</widget>
</item>

5
conf/okular_core.kcfg
Unescape View File

@ -54,6 +54,11 @@
<choice name="Paper" />
<choice name="Recolor" />
<choice name="BlackWhite" />
<choice name="InvertLightness" />
<choice name="InvertLuma" />
<choice name="InvertLumaSymmetric" />
<choice name="HueShiftPositive" />
<choice name="HueShiftNegative" />
</choices>
</entry>
</group>

41
doc/index.docbook
Unescape View File

@ -2334,6 +2334,47 @@ Context menu actions like Rename Bookmarks etc.)
by moving it to the right will result in lighter grays used.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><guilabel>Invert Lightness</guilabel></term>
<listitem>
<para><action>Inverts</action> lightness of all colors.
Light and dark colors will be swapped, but hue and saturation will not be affected.
The Contrast in images will usually be worse than in <guilabel>Invert Luma (sRGB Linear)</guilabel>.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><guilabel>Invert Luma (sRGB Linear)</guilabel></term>
<listitem>
<para><action>Inverts</action> luma of all colors.
Light and dark will be swapped, but hue and saturation will not be affected.
The Contrast in images is preserved better than in <guilabel>Invert Lightness</guilabel>,
but graphics and colorful text markup usually look worse.
Uses sRGB luma coefficients, but no gamma correction.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><guilabel>Invert Luma (Symmetric)</guilabel></term>
<listitem>
<para><action>Inverts</action> luma of all colors, using symmetric luma coefficients.
Light and dark will be swapped, but hue and saturation will not be affected.
Very similar to <guilabel>Invert Lightness</guilabel>,
but the contrast is in some cases better.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><guilabel>Shift Hue Positive</guilabel></term>
<listitem>
<para><action>Shifts</action> hue of all colors by 120 degrees.
Can mitigate some contrast problems in colorful graphics</para>
</listitem>
</varlistentry>
<varlistentry>
<term><guilabel>Shift Hue Negative</guilabel></term>
<listitem>
<para><action>Shifts</action> hue of all colors by 240 degrees.
Can mitigate some contrast problems in colorful graphics</para>
</listitem>
</varlistentry>
<varlistentry>
<term><guilabel>Engine</guilabel></term>
<listitem>

260
ui/pagepainter.cpp
Unescape View File

@ -371,27 +371,22 @@ void PagePainter::paintCroppedPageOnPainter( QPainter * destPainter, const Okula
recolor(&backImage, Okular::Settings::recolorForeground(), Okular::Settings::recolorBackground());
break;
case Okular::SettingsCore::EnumRenderMode::BlackWhite:
// Manual Gray and Contrast
unsigned int * data = reinterpret_cast<unsigned int *>(backImage.bits());
int val, pixels = backImage.width() * backImage.height(),
con = Okular::Settings::bWContrast(), thr = 255 - Okular::Settings::bWThreshold();
for( int i = 0; i < pixels; ++i )
{
val = qGray( data[i] );
if ( val > thr )
val = 128 + (127 * (val - thr)) / (255 - thr);
else if ( val < thr )
val = (128 * val) / thr;
if ( con > 2 )
{
val = con * ( val - thr ) / 2 + thr;
if ( val > 255 )
val = 255;
else if ( val < 0 )
val = 0;
}
data[i] = qRgba( val, val, val, 255 );
}
blackWhite(&backImage, Okular::Settings::bWContrast(), Okular::Settings::bWThreshold());
break;
case Okular::SettingsCore::EnumRenderMode::InvertLightness:
invertLightness(&backImage);
break;
case Okular::SettingsCore::EnumRenderMode::InvertLuma:
invertLuma(&backImage, 0.2126, 0.7152, 0.0722); // sRGB / Rec. 709 luma coefficients
break;
case Okular::SettingsCore::EnumRenderMode::InvertLumaSymmetric:
invertLuma(&backImage, 0.3333, 0.3334, 0.3333); // Symmetric coefficients, to keep colors saturated.
break;
case Okular::SettingsCore::EnumRenderMode::HueShiftPositive:
hueShiftPositive(&backImage);
break;
case Okular::SettingsCore::EnumRenderMode::HueShiftNegative:
hueShiftNegative(&backImage);
break;
}
}
@ -839,6 +834,229 @@ void PagePainter::recolor(QImage *image, const QColor &foreground, const QColor
}
}
void PagePainter::blackWhite(QImage *image, int contrast, int threshold)
{
unsigned int * data = reinterpret_cast<unsigned int *>(image->bits());
int con = contrast;
int thr = 255 - threshold;
int pixels = image->width() * image->height();
for ( int i = 0; i < pixels; ++i )
{
// Piecewise linear function of val, through (0, 0), (thr, 128), (255, 255)
int val = qGray( data[i] );
if ( val > thr )
val = 128 + (127 * (val - thr)) / (255 - thr);
else if ( val < thr )
val = (128 * val) / thr;
// Linear contrast stretching through (thr, thr)
if ( con > 2 )
{
val = thr + ( val - thr ) * con / 2;
val = qBound( 0, val, 255 );
}
data[i] = qRgba( val, val, val, 255 );
}
}
void PagePainter::invertLightness(QImage* image)
{
if (image->format() != QImage::Format_ARGB32_Premultiplied) {
qCWarning(OkularUiDebug) << "Wrong image format! Converting...";
*image = image->convertToFormat(QImage::Format_ARGB32_Premultiplied);
}
Q_ASSERT(image->format() == QImage::Format_ARGB32_Premultiplied);
QRgb * data = reinterpret_cast<QRgb*>(image->bits());
int pixels = image->width() * image->height();
for ( int i = 0; i < pixels; ++i )
{
// Invert lightness of the pixel using the cylindric HSL color model.
// Algorithm is based on https://en.wikipedia.org/wiki/HSL_and_HSV#HSL_to_RGB (2019-03-17).
// Important simplifications are that inverting lightness does not change chroma and hue.
// This means the sector (of the chroma/hue plane) is not changed,
// so we can use a linear calculation after determining the sector using qMin() and qMax().
uchar R = qRed( data[ i ] );
uchar G = qGreen( data[ i ] );
uchar B = qBlue( data[ i ] );
// Get only the needed HSL components. These are chroma C and the common component m.
// Get common component m
uchar m = qMin( R, qMin( G, B ) );
// Remove m from color components
R -= m;
G -= m;
B -= m;
// Get chroma C
uchar C = qMax( R, qMax( G, B ) );
// Get common component m' after inverting lightness L.
// Hint: Lightness L = m + C / 2; L' = 255 - L = 255 - (m + C / 2) => m' = 255 - C - m
uchar m_ = 255 - C - m;
// Add m' to color compontents
R += m_;
G += m_;
B += m_;
// Save new color
data[i] = qRgba( R, G, B, 255 );
}
}
void PagePainter::invertLuma(QImage* image, float Y_R, float Y_G, float Y_B)
{
if (image->format() != QImage::Format_ARGB32_Premultiplied) {
qCWarning(OkularUiDebug) << "Wrong image format! Converting...";
*image = image->convertToFormat(QImage::Format_ARGB32_Premultiplied);
}
Q_ASSERT(image->format() == QImage::Format_ARGB32_Premultiplied);
QRgb * data = reinterpret_cast<QRgb*>(image->bits());
int pixels = image->width() * image->height();
for ( int i = 0; i < pixels; ++i )
{
uchar R = qRed( data[ i ] );
uchar G = qGreen( data[ i ] );
uchar B = qBlue( data[ i ] );
invertLumaPixel(R, G, B, Y_R, Y_G, Y_B);
// Save new color
data[i] = qRgba( R, G, B, 255 );
}
}
void PagePainter::invertLumaPixel(uchar &R, uchar &G, uchar &B, float Y_R, float Y_G, float Y_B) {
// Invert luma of the pixel using the bicone HCY color model, stretched to cylindric HSY.
// Algorithm is based on https://en.wikipedia.org/wiki/HSL_and_HSV#Luma,_chroma_and_hue_to_RGB (2019-03-19).
// For an illustration see https://experilous.com/1/product/make-it-colorful/ (2019-03-19).
// Special case: The algorithm does not work when hue is undefined.
if (R == G && G == B) {
R = 255 - R;
G = 255 - G;
B = 255 - B;
return;
}
// Get input and output luma Y, Y_inv in range 0..255
float Y = R * Y_R + G * Y_G + B * Y_B;
float Y_inv = 255 - Y;
// Get common component m and remove from color components.
// This moves us to the bottom faces of the HCY bicone, i. e. we get C and X in R, G, B.
uint_fast8_t m = qMin( R, qMin( G, B ) );
R -= m;
G -= m;
B -= m;
// We operate in a hue plane of the luma/chroma/hue bicone.
// The hue plane is a triangle.
// This bicone is distorted, so we can not simply mirror the triangle.
// We need to stretch it to a luma/saturation rectangle, so we need to stretch chroma C and the proportional X.
// First, we need to calculate luma Y_full_C for the outer corner of the triangle.
// Then we can interpolate the max chroma C_max, C_inv_max for our luma Y, Y_inv.
// Then we calculate C_inv and X_inv by scaling them by the ratio of C_max and C_inv_max.
// Calculate luma Y_full_C (in range equivalent to gray 0..255) for chroma = 1 at this hue.
// Piecewise linear, with the corners of the bicone at the sum of one or two luma coefficients.
float Y_full_C;
if (R >= B && B >= G) {
Y_full_C = 255 * Y_R + 255 * Y_B * B / R;
} else if (R >= G && G >= B) {
Y_full_C = 255 * Y_R + 255 * Y_G * G / R;
} else if (G >= R && R >= B) {
Y_full_C = 255 * Y_G + 255 * Y_R * R / G;
} else if (G >= B && B >= R) {
Y_full_C = 255 * Y_G + 255 * Y_B * B / G;
} else if (B >= G && G >= R) {
Y_full_C = 255 * Y_B + 255 * Y_G * G / B;
} else {
Y_full_C = 255 * Y_B + 255 * Y_R * R / B;
}
// Calculate C_max, C_inv_max, to scale C and X.
float C_max, C_inv_max;
if (Y >= Y_full_C) {
C_max = Y_inv / (255 - Y_full_C);
} else {
C_max = Y / Y_full_C;
}
if (Y_inv >= Y_full_C) {
C_inv_max = Y / (255 - Y_full_C);
} else {
C_inv_max = Y_inv / Y_full_C;
}
// Scale C and X. C and X already lie in R, G, B.
float C_scale = C_inv_max / C_max;
float R_ = R * C_scale;
float G_ = G * C_scale;
float B_ = B * C_scale;
// Calculate missing luma (in range 0..255), to get common component m_inv
float m_inv = Y_inv - (Y_R * R_ + Y_G * G_ + Y_B * B_);
// Add m_inv to color compontents
R_ += m_inv;
G_ += m_inv;
B_ += m_inv;
// Return colors rounded
R = R_ + 0.5;
G = G_ + 0.5;
B = B_ + 0.5;
}
void PagePainter::hueShiftPositive(QImage* image)
{
if (image->format() != QImage::Format_ARGB32_Premultiplied) {
qCWarning(OkularUiDebug) << "Wrong image format! Converting...";
*image = image->convertToFormat(QImage::Format_ARGB32_Premultiplied);
}
Q_ASSERT(image->format() == QImage::Format_ARGB32_Premultiplied);
QRgb * data = reinterpret_cast<QRgb*>(image->bits());
int pixels = image->width() * image->height();
for ( int i = 0; i < pixels; ++i )
{
uchar R = qRed( data[ i ] );
uchar G = qGreen( data[ i ] );
uchar B = qBlue( data[ i ] );
// Save new color
data[i] = qRgba( B, R, G, 255 );
}
}
void PagePainter::hueShiftNegative(QImage* image)
{
if (image->format() != QImage::Format_ARGB32_Premultiplied) {
qCWarning(OkularUiDebug) << "Wrong image format! Converting...";
*image = image->convertToFormat(QImage::Format_ARGB32_Premultiplied);
}
Q_ASSERT(image->format() == QImage::Format_ARGB32_Premultiplied);
QRgb * data = reinterpret_cast<QRgb*>(image->bits());
int pixels = image->width() * image->height();
for ( int i = 0; i < pixels; ++i )
{
uchar R = qRed( data[ i ] );
uchar G = qGreen( data[ i ] );
uchar B = qBlue( data[ i ] );
// Save new color
data[i] = qRgba( G, B, R, 255 );
}
}
/** Private Helpers :: Image Drawing **/
// from Arthur - qt4
static inline int qt_div_255(int x) { return (x + (x>>8) + 0x80) >> 8; }

21
ui/pagepainter.h
Unescape View File

@ -56,6 +56,27 @@ class Q_DECL_EXPORT PagePainter
private:
static void cropPixmapOnImage( QImage & dest, const QPixmap * src, const QRect r );
static void recolor(QImage *image, const QColor &foreground, const QColor &background);
static void blackWhite(QImage *image, int contrast, int threshold);
static void invertLightness(QImage *image);
/**
* Inverts luma of @p image using the luma coefficients @p Y_R, @p Y_G, @p Y_B (should sum up to 1),
* and assuming linear 8bit RGB color space.
*/
static void invertLuma(QImage *image, float Y_R, float Y_G, float Y_B);
/**
* Inverts luma of a pixel given in @p R, @p G, @p B,
* using the luma coefficients @p Y_R, @p Y_G, @p Y_B (should sum up to 1),
* and assuming linear 8bit RGB color space.
*/
static void invertLumaPixel(uchar &R, uchar &G, uchar &B, float Y_R, float Y_G, float Y_B);
/**
* Shifts hue of each pixel by 120 degrees, by simply swapping channels.
*/
static void hueShiftPositive(QImage *image);
/**
* Shifts hue of each pixel by 240 degrees, by simply swapping channels.
*/
static void hueShiftNegative(QImage *image);
// set the alpha component of the image to a given value
static void changeImageAlpha( QImage & image, unsigned int alpha );

Write Preview
Loading…
Cancel
Save