QGIS API Documentation 3.40.0-Bratislava (b56115d8743)
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Contains operations and filters which apply to QImages. More...
#include <qgsimageoperation.h>
Classes | |
struct | DistanceTransformProperties |
Struct for storing properties of a distance transform operation. More... | |
Public Types | |
enum | FlipType { FlipHorizontal , FlipVertical } |
Flip operation types. More... | |
enum | GrayscaleMode { GrayscaleLightness , GrayscaleLuminosity , GrayscaleAverage , GrayscaleOff } |
Modes for converting a QImage to grayscale. More... | |
Static Public Member Functions | |
static void | adjustBrightnessContrast (QImage &image, int brightness, double contrast, QgsFeedback *feedback=nullptr) |
Alter the brightness or contrast of a QImage. | |
static void | adjustHueSaturation (QImage &image, double saturation, const QColor &colorizeColor=QColor(), double colorizeStrength=1.0, QgsFeedback *feedback=nullptr) |
Alter the hue or saturation of a QImage. | |
static void | convertToGrayscale (QImage &image, GrayscaleMode mode=GrayscaleLuminosity, QgsFeedback *feedback=nullptr) |
Convert a QImage to a grayscale image. | |
static QImage | cropTransparent (const QImage &image, QSize minSize=QSize(), bool center=false) |
Crop any transparent border from around an image. | |
static void | distanceTransform (QImage &image, const QgsImageOperation::DistanceTransformProperties &properties, QgsFeedback *feedback=nullptr) |
Performs a distance transform on the source image and shades the result using a color ramp. | |
static void | flipImage (QImage &image, FlipType type) |
Flips an image horizontally or vertically. | |
static QImage * | gaussianBlur (QImage &image, int radius, QgsFeedback *feedback=nullptr) |
Performs a gaussian blur on an image. | |
static void | multiplyOpacity (QImage &image, double factor, QgsFeedback *feedback=nullptr) |
Multiplies opacity of image pixel values by a factor. | |
static QRect | nonTransparentImageRect (const QImage &image, QSize minSize=QSize(), bool center=false) |
Calculates the non-transparent region of an image. | |
static void | overlayColor (QImage &image, const QColor &color) |
Overlays a color onto an image. | |
static void | stackBlur (QImage &image, int radius, bool alphaOnly=false, QgsFeedback *feedback=nullptr) |
Performs a stack blur on an image. | |
Contains operations and filters which apply to QImages.
A set of optimised pixel manipulation operations and filters which can be applied to QImages. All operations only apply to ARGB32 format images, and it is left up to the calling procedure to ensure that any passed images are of the correct format.
Operations are written to either modify an image in place or return a new image, depending on which is faster for the particular operation.
Definition at line 46 of file qgsimageoperation.h.
Flip operation types.
Enumerator | |
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FlipHorizontal | Flip the image horizontally. |
FlipVertical | Flip the image vertically. |
Definition at line 65 of file qgsimageoperation.h.
Modes for converting a QImage to grayscale.
Definition at line 54 of file qgsimageoperation.h.
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Alter the brightness or contrast of a QImage.
image | QImage to alter |
brightness | brightness value, in the range -255 to 255. A brightness value of 0 indicates no change to brightness, a negative value will darken the image, and a positive value will brighten the image. |
contrast | contrast value. Must be a positive or zero value. A value of 1.0 indicates no change to the contrast, a value of 0 represents an image with 0 contrast, and a value > 1.0 will increase the contrast of the image. |
feedback | optional feedback object for responsive cancellation (since QGIS 3.22) |
Definition at line 256 of file qgsimageoperation.cpp.
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Alter the hue or saturation of a QImage.
image | QImage to alter |
saturation | double between 0 and 2 inclusive, where 0 = desaturate and 1.0 = no change |
colorizeColor | color to use for colorizing image. Set to an invalid QColor to disable colorization. |
colorizeStrength | double between 0 and 1, where 0 = no colorization and 1.0 = full colorization |
feedback | optional feedback object for responsive cancellation (since QGIS 3.22) |
Definition at line 280 of file qgsimageoperation.cpp.
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Convert a QImage to a grayscale image.
Alpha channel is preserved.
image | QImage to convert |
mode | mode to use during grayscale conversion |
feedback | optional feedback object for responsive cancellation (since QGIS 3.22) |
Definition at line 195 of file qgsimageoperation.cpp.
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Crop any transparent border from around an image.
image | source image |
minSize | minimum size for cropped image, if desired. If the cropped image is smaller than the minimum size, it will be centered in the returned image. |
center | cropped image will be centered on the center of the original image if set to true |
Definition at line 959 of file qgsimageoperation.cpp.
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Performs a distance transform on the source image and shades the result using a color ramp.
image | QImage to alter |
properties | DistanceTransformProperties object with parameters for the distance transform operation |
feedback | optional feedback object for responsive cancellation (since QGIS 3.22) |
Definition at line 391 of file qgsimageoperation.cpp.
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Flips an image horizontally or vertically.
image | QImage to flip |
type | type of flip to perform (horizontal or vertical) |
Definition at line 847 of file qgsimageoperation.cpp.
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Performs a gaussian blur on an image.
Gaussian blur is slower but results in a high quality blur.
image | QImage to blur |
radius | blur radius in pixels |
feedback | optional feedback object for responsive cancellation (since QGIS 3.22) |
Definition at line 655 of file qgsimageoperation.cpp.
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Multiplies opacity of image pixel values by a factor.
image | QImage to alter |
factor | factor to multiple pixel's opacity by |
feedback | optional feedback object for responsive cancellation (since QGIS 3.22) |
Definition at line 335 of file qgsimageoperation.cpp.
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Calculates the non-transparent region of an image.
image | source image |
minSize | minimum size for returned region, if desired. If the non-transparent region of the image is smaller than this minimum size, it will be centered in the returned rectangle. |
center | return rectangle will be centered on the center of the original image if set to true |
Definition at line 854 of file qgsimageoperation.cpp.
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Overlays a color onto an image.
This operation retains the alpha channel of the original image, but replaces all image pixel colors with the specified color.
image | QImage to alter |
color | color to overlay (any alpha component of the color is ignored) |
Definition at line 375 of file qgsimageoperation.cpp.
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Performs a stack blur on an image.
Stack blur represents a good balance between speed and blur quality.
image | QImage to blur |
radius | blur radius in pixels, maximum value of 16 |
alphaOnly | set to true to blur only the alpha component of the image |
feedback | optional feedback object for responsive cancellation (since QGIS 3.22) |
false
, or ARGB32 if alphaOnly is true
Definition at line 589 of file qgsimageoperation.cpp.