105932 - Inline image scaling introduces ugly aliasing

Status: RESOLVED DUPLICATE of bug 98971

(Core Graveyard :: GFX, defect)

Description

[Damian Yerrick]

From Bugzilla Helper:
User-Agent: Mozilla/5.0 (Windows; U; Win 9x 4.90; en-US; rv:0.9.5+) Gecko/20011018
BuildID:    2001101803

As imaging technologies move from pixel sizing to physical (cm, pt,
etc.) sizing, web browsers will need to resample images to the user's
display resolution.  We can no longer rely on all inline images being
created at 96 dpi, stored at 96 dpi, sent over the wire at 96 dpi, and
displayed at 96 dpi.  We can't rely on Mozilla's current "nearest
neighbor" scaling algorithm that introduces horrible aliasing artifacts
because the ugly appearance of scaled images will discourage web site
designers from using resolution-independent markup and stylesheets.


Reproducible: Always
Steps to Reproduce:
1. Download and unzip the forthcoming attached test case.
2. From Mozilla, open aliasing.html
3. Scroll down to the "Actual" images.

Actual Results:  In both quirks and standard mode, scaled images have
ugly aliasing due to nearest-neighbor resampling.  (This also happens
in MS Internet Explorer 4.0, 5.0, 5.5, and 6.0 for Win32.)

Expected Results:  Scaled images have little aliasing.

To reduce aliasing by 6 dB/octave, use bilinear interpolation instead
of nearest neighbor resampling. If this poses a performance problem,
make it a preference.

Bug 90813 covers the same problem with respect to text rather than
inline images.

Comment 1

[Damian Yerrick]

Attachment: Test case demonstrating the ugliness of nearest neighbor

Comment 2

[Boris Zbarsky [:bzbarsky]]

Duplicate of "Bilinear scaling need for line art and scalable web pages"  (which
has an implementation attached btw; it just needs to be integrated into Mozilla.

*** This bug has been marked as a duplicate of 98971 ***