/**
* @property file The file to be reduced in size. It will be overwritten with the size reduction processes.
* @property sizeLimitBytes Max size the file can be after compression.
* @property compressPriority Start reducing file size by scaling down or compressing.
* @property lowerWidthLimit Stop scaling down before dropping down below this value.
* @property lowerHeightLimit Stop scaling down before dropping down below this value.
* @property compressionQualityDownTo Lower value means lower quality and smaller size.
* @property scaleDownFactor Scale factor to divide width and height of image in every loop.
*/
class BitmapCompression(
private val file: File,
var sizeLimitBytes: Int,
var compressPriority: CompressPriority = CompressPriority.StartByCompress,
var lowerWidthLimit: Int? = null,
var lowerHeightLimit: Int? = null,
@IntRange(from = 1, to = 90)
var compressionQualityDownTo: Int = 50,
@FloatRange(from = 0.1, to = 0.9)
var scaleDownFactor: Float = 0.8f
)The BitmapCompression class provides a utility to reduce the size of the image files under a specified size limit while maintaining control over compression parameters.
In this example, size reduction starts with scaling down the file prior to compressing process, aiming to reduce the size under 1048576 bytes and prevents scaling the image width down below 1920 pixels. If the size reduction can't succeed, lowerWidthLimit is being set to a lower level and compressAndScaleDown function is invoked again so that the size can be reduced under the specified size limit.
val compression = BitmapCompression(
file = tempFile,
sizeLimitBytes = 1048576,
compressPriority = BitmapCompression.CompressPriority.StartByScaleDown,
lowerWidthLimit = 1920,
compressionQualityDownTo = 85
)
try {
compression.compressAndScaleDown()
} catch (exception: SizeException) {
compression.lowerWidthLimit = 1280
compression.compressAndScaleDown()
}Scale down a bitmap or a file preserving the aspect ratio.
val scaledDownToFullHdBitmap = BitmapCompression.scaleDownToWidth(bitmap, 1920)BitmapCompression.scaleDownToWidth(tempFile, 1920)val scaledDownToFullHdBitmap = BitmapCompression.scaleDownToHeight(bitmap, 1080)BitmapCompression.scaleDownToHeight(tempFile, 1080)You can build the library and use it as an aar in a project.
Copyright 2024 Mustafa Utku Ensert
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.