Rendering of heavily-resized image is poor as compared to Opera 9.51




10 years ago
8 years ago


(Reporter: Helge Skjeveland, Unassigned)


1.9.0 Branch
Windows XP

Firefox Tracking Flags

(Not tracked)




(3 attachments)



10 years ago
User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9) Gecko/2008052906 Firefox/3.0
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9) Gecko/2008052906 Firefox/3.0

Aliasing dropouts result in poor rendering of fine detail in <img>s.  Load the page in the URL above and look at its <img>-embedded music-notation <img> (style="width: 770px height: auto;"): At default zoom, thin lines (e.g., staff lines, note stems) drop out.  Even when using {Ctrl}+ to zoom in repeatedly to maximum, some staff lines and note stems still disappear (in-between pixels?).  This does not happen in Opera 9.51, whose display of this .png is superb even at default zoom, as it seems to use the similarly better anti-aliasing (dropout) handling as Acrobat 8. These apps' renderers seem to more accurately shift on/off pixels to avoid dropout (anti-aliasing). FF 3 is here rendering just as poorly as MSIE 8β, by the way...

This may be related to another problem:  Click on the image itself to invoke the anchor in which the <img> is embedded, which displays the .png image file in the browser window, raw.  In this state, Zoom {Ctrl}+ first jumps to a HUGE zoom from the default, and then steps through greater zooms, rather than stepwise as View | Zoom | In and | Out does, which hints there may be a problem in the zoom/rendering code. It seems to me that it worked better during beta.

Should I file the second problem as a different bug?

Reproducible: Always

Steps to Reproduce:
1. Load,%20Come,%20Ye%20Saints/notation.htm into FF3
2. Play around with zoom as described above, and note <sorry> dropouts of thin lines in .png displayed in anchor.
3. Click anchor, play around with raw .png zoom to notice anomalous behavior as described, and repeat of poor rendering at default zoom level.
Actual Results:  
Poor rendering (aliasing dropouts) of thin lines/detail, and anomalous behavior of zoom of raw image.

Expected Results:  
Thin lines should be shifted to pixels or duplicated at half intensity with anti-aliasing as per Opera 9.51 and Acrobat 8+.

Graphics hardware: Diamond Stealth X1050 graphics card, AMD/ATI 8.5 Catalyst video suite, but Acrobat displays it fine (,%20Come,%20Ye%20Saints/Come,%20Come,%20Ye%20Saints.pdf), as does Opera 9.51.

Comment 1

10 years ago
Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.4; en-US; rv:1.9.1a1pre) Gecko/2008071602 Minefield/3.1a1pre

I filed bug 445888 for another problem I noticed at this URL (on Mac).

I'm not seeing missing lines at any zoom level, including the default (modulo bug 445888).  Given that bug 381661 was fixed for Firefox 3, I wonder what's wrong on Windows.
Component: General → GFX: Thebes
Product: Firefox → Core
QA Contact: general → thebes
Summary: Rendering of graphic images is poor as compared to Opera 9.51 → Rendering of heavily-resized image is poor as compared to Opera 9.51
Version: unspecified → 1.9.0 Branch

Comment 2

10 years ago
Jesse is right:  The image is a 300DPI .png for a 8½" &times; 11" canvas, in order to give best quality for printing directly.  Point is: it's displayed with great quality in Opera 9.51, and such 300DPI .pngs and .gifs seemed to display much better in beta than with the released code.  Screen shots of default zoom and at full zoom can be seen at

Screenshots of Opera 9.51 display of the notation .pngs are at similar URLs, with Opera_ pre-pended to the file name.

Comment 3

8 years ago
Created attachment 444654 [details]
Opera 10.53 on Windows XP at 120% zoom level

Comment 4

8 years ago
Created attachment 444655 [details]
Internet Explorer 7 on Windows XP at 120% zoom level

Comment 5

8 years ago
Created attachment 444656 [details]
Google Chrome 4.1.x on Windows XP at 120% zoom level

Comment 6

8 years ago
Confirmed on Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv: Gecko/20100401 Firefox/3.6.3.

Just for comparison, the same problem is reproducible with Opera 10.53; as opposite IE7 and Google Chrome zoom it right.

Changing status to NEW.
Ever confirmed: true
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