[DOC] Builtin image data augmentation functions
* img_brightness()
* img_crop()
* img_mirror()
Closes #959.
diff --git a/dev/docs/builtins-reference.md b/dev/docs/builtins-reference.md
index a92fa75..8ea0e31 100644
--- a/dev/docs/builtins-reference.md
+++ b/dev/docs/builtins-reference.md
@@ -26,6 +26,9 @@
* [`confusionMatrix`-Function](#confusionmatrix-function)
* [`glm`-Function](#glm-function)
* [`gridSearch`-Function](#gridSearch-function)
+ * [`img_brightness`-Function](#img_brightness-function)
+ * [`img_crop`-Function](#img_crop-function)
+ * [`img_mirror`-Function](#img_mirror-function)
* [`KMeans`-Function](#KMeans-function)
* [`lm`-Function](#lm-function)
* [`lmDS`-Function](#lmds-function)
@@ -234,6 +237,91 @@
[B, opt]= gridSearch(X=X, y=y, train="lm", predict="lmPredict", params=params, paramValues=paramRanges, verbose = TRUE)
```
+## `img_brightness`-Function
+
+The `img_brightness`-function is an image data augumentation function.
+It changes the brightness of the image.
+
+### Usage
+```r
+img_brightness(img_in, value, channel_max)
+```
+
+### Arguments
+| Name | Type | Default | Description |
+| :---------- | :------------- | -------- | :---------- |
+| img_in | Matrix[Double] | --- | Input matrix/image |
+| value | Double | --- | The amount of brightness to be changed for the image |
+| channel_max | Integer | --- | Maximum value of the brightness of the image |
+
+### Returns
+| Name | Type | Default | Description |
+| :------ | :------------- | -------- | :---------- |
+| img_out | Matrix[Double] | --- | Output matrix/image |
+
+### Example
+```r
+A = rand(rows = 3, cols = 3, min = 0, max = 255)
+B = img_brightness(img_in = A, value = 128, channel_max = 255)
+```
+
+## `img_crop`-Function
+
+The `img_crop`-function is an image data augumentation function.
+It cuts out a subregion of an image.
+
+### Usage
+```r
+img_crop(img_in, w, h, x_offset, y_offset)
+```
+
+### Arguments
+| Name | Type | Default | Description |
+| :------ | :------------- | -------- | :---------- |
+| img_in | Matrix[Double] | --- | Input matrix/image |
+| w | Integer | --- | The width of the subregion required |
+| h | Integer | --- | The height of the subregion required |
+| x_offset | Integer | --- | The horizontal coordinate in the image to begin the crop operation |
+| y_offset | Integer | --- | The vertical coordinate in the image to begin the crop operation |
+
+### Returns
+| Name | Type | Default | Description |
+| :------ | :------------- | ------- | :---------- |
+| img_out | Matrix[Double] | --- | Cropped matrix/image |
+
+### Example
+```r
+A = rand(rows = 3, cols = 3, min = 0, max = 255)
+B = img_crop(img_in = A, w = 20, h = 10, x_offset = 0, y_offset = 0)
+```
+
+## `img_mirror`-Function
+
+The `img_mirror`-function is an image data augumentation function.
+It flips an image on the `X` (horizontal) or `Y` (vertical) axis.
+
+### Usage
+```r
+img_mirror(img_in, horizontal_axis)
+```
+
+### Arguments
+| Name | Type | Default | Description |
+| :-------------- | :------------- | -------- | :---------- |
+| img_in | Matrix[Double] | --- | Input matrix/image |
+| horizontal_axis | Boolean | --- | If TRUE, the image is flipped with respect to horizontal axis otherwise vertical axis |
+
+### Returns
+| Name | Type | Default | Description |
+| :------ | :------------- | -------- | :---------- |
+| img_out | Matrix[Double] | --- | Flipped matrix/image |
+
+### Example
+```r
+A = rand(rows = 3, cols = 3, min = 0, max = 255)
+B = img_mirror(img_in = A, horizontal_axis = TRUE)
+```
+
## `KMeans`-Function
The kmeans() implements the KMeans Clustering algorithm.
