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Fix for blurry images from WEBP input and small output dimensions #368

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Merged
h2non merged 2 commits into from
Aug 7, 2021
Merged

Fix for blurry images from WEBP input and small output dimensions #368

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c51a11f
Fix for blurry images from WEBP input and small output dimensions
totallyunknown Mar 31, 2021
401c985
Remove debug output
totallyunknown Mar 31, 2021
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47 changes: 27 additions & 20 deletions resizer.go
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Original file line number Diff line number Diff line change
Expand Up @@ -449,29 +449,36 @@ func shrinkImage(image *C.VipsImage, o Options, residual float64, shrink int) (*
}

func shrinkOnLoad(buf []byte, input *C.VipsImage, imageType ImageType, factor float64, shrink int) (*C.VipsImage, float64, error) {
var image *C.VipsImage
var err error
var (
image *C.VipsImage
err error
)

// Reload input using shrink-on-load
if imageType == JPEG && shrink >= 2 {
shrinkOnLoad := 1
// Recalculate integral shrink and double residual
switch {
case shrink >= 8:
factor = factor / 8
shrinkOnLoad = 8
case shrink >= 4:
factor = factor / 4
shrinkOnLoad = 4
case shrink >= 2:
factor = factor / 2
shrinkOnLoad = 2
}
if shrink < 2 {
return nil, 0, fmt.Errorf("only available for shrink >=2")
}

shrinkOnLoad := 1
// Recalculate integral shrink and double residual
switch {
case shrink >= 8:
factor = factor / 8
shrinkOnLoad = 8
case shrink >= 4:
factor = factor / 4
shrinkOnLoad = 4
case shrink >= 2:
factor = factor / 2
shrinkOnLoad = 2
}

// Reload input using shrink-on-load
switch imageType {
case JPEG:
image, err = vipsShrinkJpeg(buf, input, shrinkOnLoad)
} else if imageType == WEBP {
image, err = vipsShrinkWebp(buf, input, shrink)
} else {
case WEBP:
image, err = vipsShrinkWebp(buf, input, shrinkOnLoad)
default:
return nil, 0, fmt.Errorf("%v doesn't support shrink on load", ImageTypeName(imageType))
}

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