36026 - Images display with horizontal "banding"

Status: VERIFIED WORKSFORME

(Core Graveyard :: GFX, defect, P3)

Description

[Adam]

Mozilla M16 2000041608, Mac OS 9.0.4 - When Mozilla loads a page with images that 
are reasonably sized (not super-tiny-load-in-one-second images), a portion of the 
image will draw to the sreen (as Mozilla draws the amount of data it's received 
so far) and then, when it receives the rest of the image data, it draws the whole 
picture. However, between the first part drawn to the screen and the subsequent 
parts, there are white bands in the image.

This always happens on the b&w microscopic Bugzilla image and just about every 
other image on the web.

Results: Images render with white horizontal lines (bands) through them.

Expectations: Images would load without white horizontal lines (bands) through 
them.

BTW, this began happening shortly before the NS preview was released and, at 
first, the images were drawn with the bands but were refreshed once the page 
loaded entirely and the banding goes away. Now it seems like the whole images/
page aren't being refreshed once loading completes.

Comment 1

[Brett Koonce]

I don't notice this at all, but I'm on an OC3.  Is download speed a factor here?

Comment 2

[Adam]

I would think so. This happens to me on my G4 - 56K connection. Haven't tried on 
my business machine here @ T1.

Comment 3

[Adam]

Attachment: Picture of banding in image

Comment 4

[Adam]

I added a pic (I'm NOT crazy!?!?!) but, after further examination, this problem 
only seems to happen when loading JPEGs so this might belong to ImageLib.

Comment 5

[Sean Richardson]

I know I've seen this sort of problem in earlier builds, but nothing of the sort
is happening with 2000-04-16-16-M16 on WinNT, nor has it for some time.
This may be Mac-only.

Comment 6

[Brett Koonce]

I would guess what needs to be done, then, is to force a refresh of a jpeg if 
downloading it took more than say, 5 seconds.  Does this go away on a refresh?  
Can you d/l the image fine manually? Or is it always messed up on your browser?

Comment 7

[Adam]

The banding does indeed go away after refreshing (reload, minimize then resize 
the window, etc.). Afterwards, the image displays fine. The JPEGs always display 
banding whether they're viewed inline or separate .jpg files. Checking to see 
effect of compression (progressive vs. normal JPEG 6, etc.) as not all JPEGs 
display this behavior (but the majority do).

Comment 8

[Kevin McCluskey (gone)]

Rod, I think this is a dup of a bug you already have.

Comment 9

[rods (gone)]

don, here you go

Comment 10

[dcone (gone)]

This bug has been marked future because we have determined that it is not 
critical for netscape 6.0.  If you feel this is an error, or if it blocks your 
work in some way -- please attach your concern to the bug for reconsideration.

Comment 11

[Sean Richardson]

This may very well be related to bug 35316, "A crash occurs when rendering a 32 
bit (640 x 480) image", nsbeta2+ -- the crash does not always happen, and when
it doesn't, only the first "band" of the image is displayed.

Comment 12

[dcone (gone)]

I don't think this is related to bug 35316.. this seems more like a clipping 
thing or something that has to do with how much of the image has been read in 
for the incremental reading of an image.

Comment 13

[Chris Petersen]

Adam,

I can't reproduce this problem in the Mac 8/22 build. Testedon G4/450 under Mac 
OS 9.0.4. Could you pull the latest Mac build to see if it's occuring.

Comment 14

[Adam]

I haven't seen this in over a month now. Somewhere along the line it must have 

been fixed.

Comment 15

[Adam]

I believe it would be safe to mark this FIXED or WORKSFORME. I haven't been
experiencing this problem in any of the recent builds. If it crops up again or
someone else is still experiencing it, it can be reopened.

Comment 16

[dcone (gone)]

I have not seen this.. marking as works for me...

Comment 17

[Adam]

Haven't seen this in 4+ months. Marking verified.

Comment 18

[luis rincon]

verified on build 2001-08-06-trunk