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Bug #8137 images are converted to wbmp as a "negative"
Submitted: 2000-12-06 12:02 UTC Modified: 2001-04-01 00:47 UTC
From: onn at zend dot com Assigned:
Status: Closed Package: GD related
PHP Version: 4.0 Latest CVS (06/12/2000) OS: linux (7.0)
Private report: No CVE-ID: None
 [2000-12-06 12:02 UTC] onn at zend dot com
when saving an image as wbmp (imagewbmp) i get the following
problems

1) if i load the image and then save it again as a jpeg,
then i will get a negative of the original.

2) when viewing the wbmp file - i viewed it at
http://www.teraflops.com/wbmp/ - i get the same "negative"
result :)

the following script demonstrates:

<?php

    $im = ImageCreate(200, 200);
    $black = ImageColorAllocate($im,0,0,0);
    $white = ImageColorAllocate($im,255,255,255);

    ImageLine($im, 0, 0, 199, 199, $white);
// create the wmbp file
    ImageWbmp($im,"../tmp/tmp_ImageCreateFromWbmp1.bmp");

// load it from disk
$im2 =
ImageCreateFromWbmp("../tmp/tmp_ImageCreateFromWbmp1.bmp");

// save as jpeg and wbmp again

    ImageWbmp($im2,"../tmp/tmp_ImageCreateFromWbmp2.bmp");
    ImageJpeg($im2,"../tmp/tmp_ImageCreateFromWbmp3.jpeg");

    ImageDestroy($im);
    ImageDestroy($im2);
?>

i would expect to see white diagnol across a black
backgrouond, but what i get the opposite - black diagonal
across a white background

the problem seems to be in the function:
_php_image_output_wbmp.

the following code
if(im->pixels[y][x] == 0) c = c | (1 << (7-p));
should be (i think)
if(im->pixels[y][x] != 0) c = c | (1 << (7-p));

(a != instead of an ==)

this gets the jpeg to be displayed correctly, but the wbmp
is still backwards (therefore not a complete fix??)

ONn


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 [2001-04-01 00:47 UTC] sniper@php.net
Fixed in CVS. (fix will be in 4.0.6)

--Jani

 
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