init pr

Author: WeichenXu123

mllib/src/main/scala/org/apache/spark/ml/image/ImageSchema.scala

@@ -35,6 +35,8 @@ import org.apache.spark.sql.types._
  */
 @Experimental
 @Since("2.3.0")
+@deprecated("use `spark.read.format(\"image\").load(path)` and this `ImageSchema` will be " +
+  "removed in 3.0.0.", "2.4.0")
 object ImageSchema {
 
   val undefinedImageType = "Undefined"

python/pyspark/ml/image.py

@@ -20,6 +20,9 @@
 
     An attribute of this module that contains the instance of :class:`_ImageSchema`.
 
+.. note:: Deprecated in 2.4.0. Use `spark.read.format("image").load(path)` instead and
+    this :py:attribute:`ImageSchema` will be removed in 3.0.0.
+
 .. autoclass:: _ImageSchema
    :members:
 """