Add exact cover fit option for device-sized cover cropping (#1254)

* Add exact cover fit option for device-sized cover cropping

* Update README to move cover cropping from FAQ to USAGE

* rename to coverfill

* edit readme

README.md

@@ -269,6 +269,7 @@ PROCESSING:
                         Crop empty sections. 0: Disabled 1: Horizontally 2: Both [Default=0]
   --blackborders        Disable autodetection and force black borders
   --whiteborders        Disable autodetection and force white borders
+  --coverfill           Center-crop only the cover to fill target device screen
   --forcecolor          Don't convert images to grayscale
   --forcepng            Create PNG files instead JPEG
   --mozjpeg             Create JPEG files using mozJpeg

gui/KCC.ui

@@ -908,6 +908,17 @@ Useful for really weird PDFs.</string>
          </property>
         </widget>
        </item>
+       <item row="9" column="1">
+        <widget class="QCheckBox" name="coverFillBox">
+         <property name="toolTip">
+          <string>Resize cover to exact device resolution by center-cropping to aspect ratio first.
+May crop top/bottom or left/right depending on source aspect ratio.</string>
+         </property>
+         <property name="text">
+          <string>Cover Fill</string>
+         </property>
+        </widget>
+       </item>
       </layout>
      </widget>
     </item>
@@ -1037,6 +1048,7 @@ Useful for really weird PDFs.</string>
   <tabstop>noRotateBox</tabstop>
   <tabstop>interPanelCropBox</tabstop>
   <tabstop>metadataTitleBox</tabstop>
+  <tabstop>coverFillBox</tabstop>
   <tabstop>chunkSizeCheckBox</tabstop>
   <tabstop>chunkSizeBox</tabstop>
   <tabstop>eraseRainbowBox</tabstop>

kindlecomicconverter/KCC_gui.py

@@ -329,6 +329,8 @@ class WorkerThread(QThread):
             options.noprocessing = True
         if GUI.pdfExtractBox.isChecked():
             options.pdfextract = True
+        if GUI.coverFillBox.isChecked():
+            options.coverfill = True
         if GUI.metadataTitleBox.checkState() == Qt.CheckState.PartiallyChecked:
             options.metadatatitle = 1
         elif GUI.metadataTitleBox.checkState() == Qt.CheckState.Checked:
@@ -1036,6 +1038,7 @@ class KCCGUI(KCC_ui.Ui_mainWindow):
                                            'eraseRainbowBox': GUI.eraseRainbowBox.checkState(),
                                            'disableProcessingBox': GUI.disableProcessingBox.checkState(),
                                            'pdfExtractBox': GUI.pdfExtractBox.checkState(),
+                                           'coverFillBox': GUI.coverFillBox.checkState(),
                                            'metadataTitleBox': GUI.metadataTitleBox.checkState(),
                                            'mozJpegBox': GUI.mozJpegBox.checkState(),
                                            'jpegQualityBox': GUI.jpegQualityBox.checkState(),

kindlecomicconverter/KCC_ui.py

@@ -467,6 +467,11 @@ class Ui_mainWindow(object):
 
         self.gridLayout_2.addWidget(self.pdfExtractBox, 9, 0, 1, 1)
 
+        self.coverFillBox = QCheckBox(self.optionWidget)
+        self.coverFillBox.setObjectName(u"coverFillBox")
+
+        self.gridLayout_2.addWidget(self.coverFillBox, 9, 1, 1, 1)
+
 
         self.gridLayout.addWidget(self.optionWidget, 5, 0, 1, 2)
 
@@ -549,7 +554,8 @@ class Ui_mainWindow(object):
         QWidget.setTabOrder(self.fileFusionBox, self.noRotateBox)
         QWidget.setTabOrder(self.noRotateBox, self.interPanelCropBox)
         QWidget.setTabOrder(self.interPanelCropBox, self.metadataTitleBox)
-        QWidget.setTabOrder(self.metadataTitleBox, self.chunkSizeCheckBox)
+        QWidget.setTabOrder(self.metadataTitleBox, self.coverFillBox)
+        QWidget.setTabOrder(self.coverFillBox, self.chunkSizeCheckBox)
         QWidget.setTabOrder(self.chunkSizeCheckBox, self.chunkSizeBox)
         QWidget.setTabOrder(self.chunkSizeBox, self.eraseRainbowBox)
         QWidget.setTabOrder(self.eraseRainbowBox, self.rotateFirstBox)
@@ -744,6 +750,11 @@ class Ui_mainWindow(object):
 "Useful for really weird PDFs.", None))
 #endif // QT_CONFIG(tooltip)
         self.pdfExtractBox.setText(QCoreApplication.translate("mainWindow", u"PDF Legacy Extract", None))
+#if QT_CONFIG(tooltip)
+        self.coverFillBox.setToolTip(QCoreApplication.translate("mainWindow", u"Resize cover to exact device resolution by center-cropping to aspect ratio first.\n"
+"May crop top/bottom or left/right depending on source aspect ratio.", None))
+#endif // QT_CONFIG(tooltip)
+        self.coverFillBox.setText(QCoreApplication.translate("mainWindow", u"Cover Fill", None))
         self.gammaLabel.setText(QCoreApplication.translate("mainWindow", u"Gamma: Auto", None))
         self.jpegQualityLabel.setText(QCoreApplication.translate("mainWindow", u"JPEG Quality:", None))
     # retranslateUi

kindlecomicconverter/comic2ebook.py

@@ -1360,6 +1360,8 @@ def makeParser():
                                     help="Do not modify image and ignore any profile or processing option")
     processing_options.add_argument("--pdfextract", action="store_true", dest="pdfextract", default=False,
                                     help="Use the legacy PDF image extraction method from KCC 8 and earlier")
+    processing_options.add_argument("--coverfill", action="store_true", dest="coverfill", default=False,
+                                    help="Crop cover to fill screen")
     processing_options.add_argument("-u", "--upscale", action="store_true", dest="upscale", default=False,
                                     help="Resize images smaller than device's resolution")
     processing_options.add_argument("-s", "--stretch", action="store_true", dest="stretch", default=False,

kindlecomicconverter/image.py

@@ -569,7 +569,10 @@ class Cover:
         if self.options.kindle_scribe_azw3:
             size[0] = min(size[0], 1920)
             size[1] = min(size[1], 1920)
-        self.image.thumbnail(tuple(size), Image.Resampling.LANCZOS)
+        if self.options.coverfill:
+            self.image = ImageOps.fit(self.image, tuple(size), Image.Resampling.LANCZOS, centering=(0.5, 0.5))
+        else:
+            self.image.thumbnail(tuple(size), Image.Resampling.LANCZOS)
 
     def crop_main_cover(self):
         w, h = self.image.size