Grayscaling images causes mangled image + segfault

[comp.lang.php]

[php]
/**
* Class for grayscaling image
*
* @author Phil Powell
* @version 1.2.1
* @package IMAGE_CATALOG:: IMAGE
*/
class ImageGrayscaleG enerator extends ImageResizeComp onents {

/
*----------------------------------------------------------------------------------------------------------------------------------------------------------
This class exists due to the rather poor performance of the
imagecopymergeg ray() command
Borrowing code snippet from http://us3.php.net/manual/en/functio...ymergegray.php
first line comment
Will perform actual grayscaling of image one pixel at a time.
-----------------------------------------------------------------------------------------------------------------------------------------------------------
*/
// REMEMBER TO USE REFERENCE POINTER ONTO $image OBJECT TO ENSURE
"static" CHANGE TO OBJECT AND NOT TO INSTANCE

/**
* Constructor. Set all properties dynamically
*
* @access public
* @param resource $image (reference)
* @param resource $newImage (reference)
* @param int $image_width
* @param int $image_height
*/
function ImageGrayscaleG enerator(&$imag e, &$newImage, $image_width,
$image_height) { // CONSTRUCTOR
global $section;
foreach (array($section , 'newImage', "${section}_wid th", "$
{section}_heigh t") as $val) $this->$val =& ${$val};
}

/**
* Make the image grayscale
*
* @access protected
*/
function makeGray() { // VOID METHOD
global $section;
for ($i = 0; $i <= 255; $i++) $colorNDX[$i] =
@imagecolorallo cate($this->newImage, $i, $i, $i);

if (is_array($colo rNDX) && @sizeof($colorN DX) 0) {
for ($y = 0; $y < $this->{$section . '_height'}; $y++) {
for ($x = 0; $x < $this->{$section . '_width'}; $x++) {
$ndx = @imagecolorat($ this->image, $x, $y);
$ndxColorArray = @imagecolorsfor index($this->image, $ndx);
$avg = floor(($ndxColo rArray['red'] + $ndxColorArray['green'] +
$ndxColorArray['blue']) / 3);
@imagesetpixel( $this->newImage, $x, $y, $colorNDX[$avg]);
}
}
}
}
}

if ($this->isSuccessful && $image && $willGrayscale) { // GRAYSCALE
IMAGE
$igg =& new ImageGrayscaleG enerator($image , $newImage,
$image_width, $image_height);
$igg->makeGray();
$igg = null;
}
[/php]

Whenever I run this class to grayscale an image, I wind up with the
resulting image being horribly mangled to the point of its original
format completely irreparable, furthermore, I wind up with an Apache
segfault and having to reboot the server to correct the problem.

Um, why?

Phil

[Steve]

"comp.lang. php" <ph************ **@gmail.comwro te in message
news:11******** **************@ o5g2000hsb.goog legroups.com...
| On Apr 16, 12:05 am, "comp.lang. php" <phillip.s.pow. [e-mail]>
| wrote:
| On Apr 15, 11:52 pm, "Steve" <no....@example .comwrote:
| >
| | You struck out. imagecopymergeg ray() fails as well, produces a
total
| | non-image with segfault just as much as anything I have done. So
much
| | for your brilliant cocky strategy. Try again.
| >
| well as EVERYTHING i've pointed out as WRONG with the class REMAINS
VALID,
| i'd say i've just stepped up to the plate. if you wanna play
hard-ball, you
| need to be a better pitcher and quit reff-ing since the strike-outs
belong
| to the class creator and NOT me.
| >
| you've merely pitched BALL ONE.
| >
| try again.
|
| Original thread that provided solution:
| http://coding.derkeiler.com/Archive/...4-02/0459.html

i don't care if gawd herself wrote it, it is STILL shit. glad to see though
that PHIL makes an EXACT COPY of SOMEONE ELSE'S code, then puts HIMSELF AS
THE AUTHOR when he (YOU) present it here. no wonder the commented
explanation shows complete lack of understanding of how references work. you
don't understand the code you copied.

BALL THREE.

| >
| You haven't even tried in the first place, or, do you even want to? If
| not, please do not waste bandwith by showing your technological
| bravado and try to help someone out with a problem with grayscaling
| images. How would YOU do it?

btw, it's MY FUCKING BANDWIDTH...go buy your own. until you pay for MINE,
YOU HAVE NO SAY IN HOW I USE IT.

[Steve]

"comp.lang. php" <ph************ **@gmail.comwro te in message
news:11******** **************@ n76g2000hsh.goo glegroups.com.. .
| On Apr 15, 11:49 pm, "Steve" <no....@example .comwrote:
| "comp.lang. php" <phillip.s.pow. [e-mail] te in message
| >
| news:11******** **************@ q75g2000hsh.goo glegroups.com.. .
| | How does "for all the 'performance' reasons the brain-dead author
| | gives for creating
| | this beast" help anyone? Thank you for utterly useless ad-hominem
| | information!
| >
| well <as he scratches his head>, it kind of warns you NOT to use the
code,
| as in solving your current problem will not solve the others you will
have
| when you employ this class. but i though that was apparent in the
examples i
| gave to support my opinion.
| >
| i'm now assuming you are said brain-dead author since you glossed over
the
| litany of things-gone-wrong in the code that i pointed out and have
| immediately championed a defensive attitude.
|
| So I assume you feel calling someone "brain-dead" is your way of
| assuming they are receptive to your solutions, whatever they may be,
| which, as I can see, do not yet exist by your means.

you post as 'comp.lang.php' not as PHIL (author of the shitty class).
knowing this know, both of us, does the code change somehow such that it
isn't shitty...enough where i should justifiably refrain from calling it
shitty? having seen that this is NOT PHIL'S code in the first place (thanks
for outting yourself with the link), i can only be MORE correct in the use
of "brain-dead" since you try to pass it off as your own.

BALL FOUR...i can take my base now.

keep racking 'em up, PHIL.

[Steve]

hey genious, here's an RBI:

foreach (
array(
$section ,
'newImage' ,
"${section}_wid th" ,
"${section}_hei ght"
)
as $val
){ $this->$val =& ${$val}; }

what do you intend to do with this lil' gem, eh? you do realize you'll get
the same results by just:

$this->val =& "${section}_hei ght";

ahhh, so when you plagerized the functionality, you copied it
incorrectly...i see.

ROFLMFAO !!!

[Steve]

"Steve" <no****@example .comwrote in message
news:m_******** *******@newsfe0 2.lga...
| hey genious, here's an RBI:
|
| foreach (
| array(
| $section ,
| 'newImage' ,
| "${section}_wid th" ,
| "${section}_hei ght"
| )
| as $val
| ){ $this->$val =& ${$val}; }
|
| what do you intend to do with this lil' gem, eh? you do realize you'll get
| the same results by just:
|
| $this->val =& "${section}_hei ght";

make that:

$this->$val =& ${"${section}_h eight"};

but you get my point. if you want to make the values into variables, do
it...but don't confuse the issue of what $this->$val is. this is right up
there with magic numbers! gotta love coders like you. ;^)

[comp.lang.php]

On Apr 16, 1:41 am, "Steve" <no....@example .comwrote:

hey genious, here's an RBI:

foreach (
array(
$section ,
'newImage' ,
"${section}_wid th" ,
"${section}_hei ght"
)
as $val
){ $this->$val =& ${$val}; }

what do you intend to do with this lil' gem, eh? you do realize you'll get
the same results by just:

$this->val =& "${section}_hei ght";

ahhh, so when you plagerized the functionality, you copied it
incorrectly...i see.

ROFLMFAO !!!

It's "genius", BTW.

[comp.lang.php]

On Apr 16, 1:47 am, "Steve" <no....@example .comwrote:

"Steve" <no....@example .comwrote in message

news:m_******** *******@newsfe0 2.lga...
| hey genious, here's an RBI:
|
| foreach (
| array(
| $section ,
| 'newImage' ,
| "${section}_wid th" ,
| "${section}_hei ght"
| )
| as $val
| ){ $this->$val =& ${$val}; }
|
| what do you intend to do with this lil' gem, eh? you do realize you'll get
| the same results by just:
|
| $this->val =& "${section}_hei ght";

make that:

$this->$val =& ${"${section}_h eight"};

but you get my point. if you want to make the values into variables, do
it...but don't confuse the issue of what $this->$val is. this is right up
there with magic numbers! gotta love coders like you. ;^)

Coders like me can spell "genius".

[Steve]

"comp.lang. php" <ph************ **@gmail.comwro te in message
news:11******** *************@l 77g2000hsb.goog legroups.com...
| On Apr 16, 1:47 am, "Steve" <no....@example .comwrote:
| "Steve" <no....@example .comwrote in message
| >
| news:m_******** *******@newsfe0 2.lga...
| | hey genious, here's an RBI:
| |
| | foreach (
| | array(
| | $section ,
| | 'newImage' ,
| | "${section}_wid th" ,
| | "${section}_hei ght"
| | )
| | as $val
| | ){ $this->$val =& ${$val}; }
| |
| | what do you intend to do with this lil' gem, eh? you do realize you'll
get
| | the same results by just:
| |
| | $this->val =& "${section}_hei ght";
| >
| make that:
| >
| $this->$val =& ${"${section}_h eight"};
| >
| but you get my point. if you want to make the values into variables, do
| it...but don't confuse the issue of what $this->$val is. this is right
up
| there with magic numbers! gotta love coders like you. ;^)
|
| Coders like me can spell "genius".

double-entandre dimwit

[Steve]

"comp.lang. php" <ph************ **@gmail.comwro te in message
news:11******** **************@ y80g2000hsf.goo glegroups.com.. .
| On Apr 16, 1:41 am, "Steve" <no....@example .comwrote:
| hey genious, here's an RBI:
| >
| foreach (
| array(
| $section ,
| 'newImage' ,
| "${section}_wid th" ,
| "${section}_hei ght"
| )
| as $val
| ){ $this->$val =& ${$val}; }
| >
| what do you intend to do with this lil' gem, eh? you do realize you'll
get
| the same results by just:
| >
| $this->val =& "${section}_hei ght";
| >
| ahhh, so when you plagerized the functionality, you copied it
| incorrectly...i see.
| >
| ROFLMFAO !!!
|
| It's "genius", BTW.

coming around the home stretch...ahhh, slides right in for another. that's 2
for home, visitors...zilc h.

you'se awr a brittun.

entendre^2...pe rhaps you've heard of it?

[Jerry Stuckle]

Steve wrote:

"comp.lang. php" <ph************ **@gmail.comwro te in message
news:11******** **************@ y80g2000hsf.goo glegroups.com.. .
| On Apr 16, 1:41 am, "Steve" <no....@example .comwrote:
| hey genious, here's an RBI:
| >
| foreach (
| array(
| $section ,
| 'newImage' ,
| "${section}_wid th" ,
| "${section}_hei ght"
| )
| as $val
| ){ $this->$val =& ${$val}; }
| >
| what do you intend to do with this lil' gem, eh? you do realize you'll
get
| the same results by just:
| >
| $this->val =& "${section}_hei ght";
| >
| ahhh, so when you plagerized the functionality, you copied it
| incorrectly...i see.
| >
| ROFLMFAO !!!
|
| It's "genius", BTW.

coming around the home stretch...ahhh, slides right in for another. that's 2
for home, visitors...zilc h.

you'se awr a brittun.

entendre^2...pe rhaps you've heard of it?

Sorry, Steve. I agree with comp.lang.php. You added absolutely nothing
to this conversation except taking up bandwidth. And it's my bandwidth,
also.

I'm glad he got this fixed in spite of your immature language and attitude.

For your next post try alt.anal.orific es. It matches you perfectly.

--
=============== ===
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
js*******@attgl obal.net
=============== ===

[comp.lang.php]

On Apr 16, 7:23 am, Jerry Stuckle <jstuck...@attg lobal.netwrote:

Steve wrote:

"comp.lang. php" <phillip.s.pow. [e-mail] te in message
news:11******** **************@ y80g2000hsf.goo glegroups.com.. .
| On Apr 16, 1:41 am, "Steve" <no....@example .comwrote:
| hey genious, here's an RBI:
| >
| foreach (
| array(
| $section ,
| 'newImage' ,
| "${section}_wid th" ,
| "${section}_hei ght"
| )
| as $val
| ){ $this->$val =& ${$val}; }
| >
| what do you intend to do with this lil' gem, eh? you do realize you'll
get
| the same results by just:
| >
| $this->val =& "${section}_hei ght";
| >
| ahhh, so when you plagerized the functionality, you copied it
| incorrectly...i see.
| >
| ROFLMFAO !!!
|
| It's "genius", BTW.

coming around the home stretch...ahhh, slides right in for another. that's 2
for home, visitors...zilc h.

you'se awr a brittun.

entendre^2...pe rhaps you've heard of it?

Sorry, Steve. I agree with comp.lang.php. You added absolutely nothing
to this conversation except taking up bandwidth. And it's my bandwidth,
also.

I'm glad he got this fixed in spite of your immature language and attitude.

Thank you, Jerry, very nice to hear this! Unfortunately no I never
did solve the problem; I am still not capable of grayscaling an image:

/**
* Make the image grayscale
*
* @access protected
*/
function makeGray() { // VOID METHOD
global $section;
for ($i = 0; $i <= 255; $i++) $colorNDX[$i] =
@imagecolorallo cate($this->$section, $i, $i, $i);

for ($y = 0; $y < $this->{$section . '_height'}; $y++) {
for ($x = 0; $x < $this->{$section . '_width'}; $x++) {
$ndx = @imagecolorat($ this->$section, $x, $y);
$red = ($ndx >16) & 0xFF;
$green = ($ndx >8) & 0xFF;
$blue = $ndx & 0xFF;
//$ndxColorArray = @imagecolorsfor index($this->$section, $ndx);
//$avg = floor(($ndxColo rArray['red'] + $ndxColorArray['green'] +
$ndxColorArray['blue']) / 3);
$col = $red * 0.299 + $green * 0.587 + $blue * 0.114;
@imagesetpixel( $this->$section, $x, $y, $colorNDX[$col]);
}
}

//@imagecopy($thi s->newImage, $this->$section, 0, 0, 0, 0,
// $this->{$section . '_width'}, $this->{$section .
'_height'});

}

No image is ever produced in spite of the code produced.

>
For your next post try alt.anal.orific es. It matches you perfectly.

--
=============== ===
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
jstuck...@attgl obal.net
=============== ===