fix: BMP output size may increase in some situations #195

Author: Donaldcwl

CHANGELOG.md

@@ -1,6 +1,7 @@
 ## 2.0.3 (TBC 2023)
 * fixed: skip copy Exif metadata when fails [#187](https://github.com/Donaldcwl/browser-image-compression/issues/187)
 * fixed: raise error if image file is corrupted / cannot be loaded [#194](https://github.com/Donaldcwl/browser-image-compression/issues/194)
+* fixed: BMP output size may increase in some situations [#195](https://github.com/Donaldcwl/browser-image-compression/issues/195)
 
 ## 2.0.2 (6 Mar 2023)
 * fixed: node version restriction [#185](https://github.com/Donaldcwl/browser-image-compression/issues/185)

lib/image-compression.js

@@ -78,6 +78,8 @@ export default async function compress(file, options, previousProgress = 0) {
   const origExceedMaxSize = tempFile.size > maxSizeByte;
   const sizeBecomeLarger = tempFile.size > file.size;
   if (process.env.BUILD === 'development') {
+    console.log('origExceedMaxSize', origExceedMaxSize);
+    console.log('sizeBecomeLarger', sizeBecomeLarger);
     console.log('outputFileType', outputFileType);
     console.log('original file size', file.size);
     console.log('current file size', tempFile.size);
@@ -100,7 +102,7 @@ export default async function compress(file, options, previousProgress = 0) {
   let newCanvas;
   let ctx;
   let canvas = orientationFixedCanvas;
-  const shouldReduceResolution = !options.alwaysKeepResolution && origExceedMaxSize;
+  const shouldReduceResolution = !options.alwaysKeepResolution && (origExceedMaxSize || outputFileType === 'image/bmp');
   while (remainingTrials-- && (currentSize > maxSizeByte || currentSize > sourceSize)) {
     const newWidth = shouldReduceResolution ? canvas.width * 0.95 : canvas.width;
     const newHeight = shouldReduceResolution ? canvas.height * 0.95 : canvas.height;