Sometimes after crop white color not white

[g-rodigy]

Describe the bug Sometimes after crop white color not white, it depends on the position crop area. It happens on all images with white color(maybe not only white, but on white color it more noticeably) only on chrome browser.

To Reproduce

const cropper = new cropperjs(document.getElementById('source'), {
  aspectRatio: 1,
  ready: function() {
    this.cropper.setCropBoxData({
      left: 72,
      top: 18,
      width: 250,
      height: 250,
    })
    
    crop()
  }
})

function crop() {
  document.getElementById('preview').src = cropper.getCroppedCanvas({
    imageSmoothingEnabled: true,
    imageSmoothingQuality: 'high',
    fillColor: '#fff',
  }).toDataURL()
}

document.getElementById('save').onclick = crop

https://codepen.io/rodigy/pen/abRRmQq

Expected behavior White color not chaged.

Desktop (please complete the following information):

• OS: Windows 10
• Browser Chrome
• Version 113

Additional context Tested on firefox, work fine

[fengyuanchen]

Can you provide some screenshots?

[g-rodigy]

Source image

Chrome

Firefox

[fengyuanchen]

How about cropper.getCroppedCanvas().toDataURL('image/jpeg')?

[g-rodigy]

No, the same with image/jpeg or image/png or image/webp

[fengyuanchen]

I have no idea about this right now...

[g-rodigy]

Later I do some tests, it maybe not a bug cropper, only browser.

[dymarchyk]

have same issue. image type "image/png" results in replacing transparent pixels to black