Re: Grayscaling Image with GD causes image to turn jet black!
Sorry I can't add that header() line, the moment I do, "index.php"
turns literally into an indiscernible JPEG image (that's assuming I'm
working with a JPEG, in my Image Catalog it could literally be
anything, even a video!)
Phil
"CountScubu la" <me@scantek.hot mail.com> wrote in message news:<VPwUb.983 0$G95.7608@news svr29.news.prod igy.com>...[color=blue]
> Like like I forgot to inflate the tire after I reinvented the wheel, forgot
> to put:
> header("Content-type: image/jpeg");
>
> --
> Mike Bradley
> http://www.gzentools.com -- free online php tools
> "Phil Powell" <soazine@erols. com> wrote in message
> news:1cdca2a7.0 402051025.2dc18 05b@posting.goo gle.com...[color=green]
> > IT WORKED AT LAST!!! Thanx a lot. By the way, your URL produced
> > ASCII-related garbage on my screen, just so you know.
> >
> > Thanx again!!
> > Phil
> >
> > "CountScubu la" <me@scantek.hot mail.com> wrote in message[/color]
> news:<vikUb.203 69$ja5.12921@ne wssvr27.news.pr odigy.com>...[color=green][color=darkred]
> > > "Phil Powell" <soazine@erols. com> wrote in message
> > > news:1cdca2a7.0 402042019.1ed5f cce@posting.goo gle.com...
> > > >
> > > > I'll show you, just go down and view...
> > > >
> > > > Phil
> > > >
> > > > < Big-O-snip >
> > >
> > > Sometimes easier to re-invent the wheel (thats my my cars don't have[/color][/color]
> model-t[color=green][color=darkred]
> > > wheels on them)
> > > here is some code that works, and you can test here:
> > > http://www.gzentools.com/test/img2gry.php
> > >
> > >
> > >
> > > <?php
> > >
> > > $imgFile = "girl1.jpg" ;
> > >
> > > $imSrc = imagecreatefrom jpeg($imgFile);
> > >
> > > $imW = imagesx($imSrc) ;
> > > $imH = imagesy($imSrc) ;
> > >
> > > $imDst = imagecreate($im W,$imH);
> > >
> > > // create 256 shades of grey
> > > for ($i=0; $i<256; $i++) {
> > > $colorNdx[$i] = imagecoloralloc ate($imDst,$i,$ i,$i);
> > > }
> > >
> > > for ($y=0; $y<$imH; $y++)
> > > {
> > > for ($x=0; $x<$imW; $x++)
> > > {
> > > $ndx = imagecolorat($i mSrc,$x,$y);
> > > $ndxColors = imagecolorsfori ndex($imSrc,$nd x);
> > > $avg = floor( ($ndxColors['red'] + $ndxColors['green'] +
> > > $ndxColors['blue']) / 3 );
> > > imagesetpixel($ imDst,$x,$y,$co lorNdx[$avg]);
> > > }
> > > }
> > >
> > > imagejpeg($imDs t);
> > > exit();
> > >
> > > ?>[/color][/color][/color]
-
Guest replied -
Guest repliedRe: Grayscaling Image with GD causes image to turn jet black!
Like like I forgot to inflate the tire after I reinvented the wheel, forgot
to put:
header("Content-type: image/jpeg");
--
Mike Bradley
http://www.gzentools.com -- free online php tools
"Phil Powell" <soazine@erols. com> wrote in message
news:1cdca2a7.0 402051025.2dc18 05b@posting.goo gle.com...[color=blue]
> IT WORKED AT LAST!!! Thanx a lot. By the way, your URL produced
> ASCII-related garbage on my screen, just so you know.
>
> Thanx again!!
> Phil
>
> "CountScubu la" <me@scantek.hot mail.com> wrote in message[/color]
news:<vikUb.203 69$ja5.12921@ne wssvr27.news.pr odigy.com>...[color=blue][color=green]
> > "Phil Powell" <soazine@erols. com> wrote in message
> > news:1cdca2a7.0 402042019.1ed5f cce@posting.goo gle.com...[color=darkred]
> > >
> > > I'll show you, just go down and view...
> > >
> > > Phil
> > >
> > > < Big-O-snip >[/color]
> >
> > Sometimes easier to re-invent the wheel (thats my my cars don't have[/color][/color]
model-t[color=blue][color=green]
> > wheels on them)
> > here is some code that works, and you can test here:
> > http://www.gzentools.com/test/img2gry.php
> >
> >
> >
> > <?php
> >
> > $imgFile = "girl1.jpg" ;
> >
> > $imSrc = imagecreatefrom jpeg($imgFile);
> >
> > $imW = imagesx($imSrc) ;
> > $imH = imagesy($imSrc) ;
> >
> > $imDst = imagecreate($im W,$imH);
> >
> > // create 256 shades of grey
> > for ($i=0; $i<256; $i++) {
> > $colorNdx[$i] = imagecoloralloc ate($imDst,$i,$ i,$i);
> > }
> >
> > for ($y=0; $y<$imH; $y++)
> > {
> > for ($x=0; $x<$imW; $x++)
> > {
> > $ndx = imagecolorat($i mSrc,$x,$y);
> > $ndxColors = imagecolorsfori ndex($imSrc,$nd x);
> > $avg = floor( ($ndxColors['red'] + $ndxColors['green'] +
> > $ndxColors['blue']) / 3 );
> > imagesetpixel($ imDst,$x,$y,$co lorNdx[$avg]);
> > }
> > }
> >
> > imagejpeg($imDs t);
> > exit();
> >
> > ?>[/color][/color]
Leave a comment:
-
Guest repliedRe: Grayscaling Image with GD causes image to turn jet black!
IT WORKED AT LAST!!! Thanx a lot. By the way, your URL produced
ASCII-related garbage on my screen, just so you know.
Thanx again!!
Phil
"CountScubu la" <me@scantek.hot mail.com> wrote in message news:<vikUb.203 69$ja5.12921@ne wssvr27.news.pr odigy.com>...[color=blue]
> "Phil Powell" <soazine@erols. com> wrote in message
> news:1cdca2a7.0 402042019.1ed5f cce@posting.goo gle.com...[color=green]
> >
> > I'll show you, just go down and view...
> >
> > Phil
> >
> > < Big-O-snip >[/color]
>
> Sometimes easier to re-invent the wheel (thats my my cars don't have model-t
> wheels on them)
> here is some code that works, and you can test here:
> http://www.gzentools.com/test/img2gry.php
>
>
>
> <?php
>
> $imgFile = "girl1.jpg" ;
>
> $imSrc = imagecreatefrom jpeg($imgFile);
>
> $imW = imagesx($imSrc) ;
> $imH = imagesy($imSrc) ;
>
> $imDst = imagecreate($im W,$imH);
>
> // create 256 shades of grey
> for ($i=0; $i<256; $i++) {
> $colorNdx[$i] = imagecoloralloc ate($imDst,$i,$ i,$i);
> }
>
> for ($y=0; $y<$imH; $y++)
> {
> for ($x=0; $x<$imW; $x++)
> {
> $ndx = imagecolorat($i mSrc,$x,$y);
> $ndxColors = imagecolorsfori ndex($imSrc,$nd x);
> $avg = floor( ($ndxColors['red'] + $ndxColors['green'] +
> $ndxColors['blue']) / 3 );
> imagesetpixel($ imDst,$x,$y,$co lorNdx[$avg]);
> }
> }
>
> imagejpeg($imDs t);
> exit();
>
> ?>[/color]
Leave a comment:
-
Guest repliedRe: Grayscaling Image with GD causes image to turn jet black!
"Phil Powell" <soazine@erols. com> wrote in message
news:1cdca2a7.0 402042019.1ed5f cce@posting.goo gle.com...[color=blue]
>
> I'll show you, just go down and view...
>
> Phil
>
> < Big-O-snip >[/color]
Sometimes easier to re-invent the wheel (thats my my cars don't have model-t
wheels on them)
here is some code that works, and you can test here:
<?php
$imgFile = "girl1.jpg" ;
$imSrc = imagecreatefrom jpeg($imgFile);
$imW = imagesx($imSrc) ;
$imH = imagesy($imSrc) ;
$imDst = imagecreate($im W,$imH);
// create 256 shades of grey
for ($i=0; $i<256; $i++) {
$colorNdx[$i] = imagecoloralloc ate($imDst,$i,$ i,$i);
}
for ($y=0; $y<$imH; $y++)
{
for ($x=0; $x<$imW; $x++)
{
$ndx = imagecolorat($i mSrc,$x,$y);
$ndxColors = imagecolorsfori ndex($imSrc,$nd x);
$avg = floor( ($ndxColors['red'] + $ndxColors['green'] +
$ndxColors['blue']) / 3 );
imagesetpixel($ imDst,$x,$y,$co lorNdx[$avg]);
}
}
imagejpeg($imDs t);
exit();
?>
--
Mike Bradley
http://www.gzentools.com -- free online php tools
Leave a comment:
-
Guest repliedRe: Grayscaling Image with GD causes image to turn jet black!
"CountScubu la" <me@scantek.hot mail.com> wrote in message news:<bEdUb.202 02$CX7.1043@new ssvr27.news.pro digy.com>...[color=blue]
> sorry, I didnt really look at the code, how is it breaking, error, not
> working?[/color]
I'll show you, just go down and view...
Phil
[color=blue]
>
> --
> Mike Bradley
> http://www.gzentools.com -- free online php tools
> "Phil Powell" <soazine@erols. com> wrote in message
> news:1cdca2a7.0 402040711.63478 c64@posting.goo gle.com...[color=green]
> > I'm sorry but that too breaks. Perhaps a code review is in order, I
> > realize that imageColorsTota l($this->image) produces 0, which I am
> > afraid I don't understand:
> >
> > class ImageGrayscaleG enerator {
> >
> >[/color]
> /*--------------------------------------------------------------------------
> ----------------------------------------------------------------------------
> ---[color=green]
> > 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.
> > --------------------------------------------------------------------------[/color]
> ----------------------------------------------------------------------------
> -----*/[color=green]
> >
> > var $image, $image_width, $image_height;
> >
> > // REMEMBER TO USE REFERENCE POINTER ONTO $image OBJECT TO ENSURE
> > "static" CHANGE TO OBJECT AND NOT TO INSTANCE
> >
> > function ImageGrayscaleG enerator(&$imag e) { // CONSTRUCTOR
> > $this->image =& $image;
> > }
> >
> > function makeGray() { // VOID METHOD
> > print_r($this->image); print_r("<P>");
> > print_r(@imageC olorsTotal($thi s->image) . "<P>");[/color][/color]
** STOP HERE! What happens is that imageColorsTota l($this->image) =
0! Though the image is in color and I do a reference pointer to the
$image resource paramters in the method call, and it actually DOES
change the image according to the value of
imageColorsTota l($this->image), it turns the entire image into one
jet-black image, no tone, no hue, nothing, a big black box.
Phil
[color=blue][color=green]
> > for ($i = 0; $i < @imagecolorstot al($this->image); $i++) {
> > $colorArray = @imageColorsFor Index($this->image, $i);
> > print_r($colorA rray); print_r("<P>");
> > $avg = floor(($colorAr ray['red'] + $colorArray['green'] +
> > $colorArray['blue']) / 3);
> > @imageColorSet( $this->image, $i, $avg, $avg, $avg);
> > }
> > }
> > }
> >
> >
> > Thanx
> > Phil
> >
> > "CountScubu la" <me@scantek.hot mail.com> wrote in message[/color]
> news:<_rSTb.197 24$up5.18401@ne wssvr27.news.pr odigy.com>...[color=green][color=darkred]
> > > Try running an average of the three colors:
> > > $avg = floor( ( $color['red']) + $color['green']) + $color['blue']) ) /[/color][/color]
> 3 )[color=green][color=darkred]
> > > $R= $avg; $B = $avg; $G = $avg;
> > > imageColorSet($ image_id, $a, $R, $G, $B);
> > >
> > >
> > > --
> > > Mike Bradley
> > > http://www.gzentools.com -- free online php tools
> > > "Phil Powell" <soazine@erols. com> wrote in message
> > > news:1cdca2a7.0 402030910.a9109 fc@posting.goog le.com...
> > > > I borrowed this code from a source:
> > > >
> > > >
> > > >
> > > > for($a=0;$a<ima gecolorstotal ($image_id);$a+ +)
> > > > {
> > > > $color = imageColorsForI ndex($image_id, $i);
> > > > $R=.299 * ($color['red'])+ .587 * ($color['green'])+ .114 *
> > > > ($color['blue']);
> > > > $G=.299 * ($color['red'])+ .587 * ($color['green'])+ .114 *
> > > > ($color['blue']);
> > > > $B=.299 * ($color['red'])+ .587 * ($color['green'])+ .114 *
> > > > ($color['blue']);
> > > > imageColorSet($ image_id, $a, $R, $G, $B);
> > > > }
> > > >
> > > > using an image (in this case I'm using a JPEG) that is a true color
> > > > image I was unable to successfully use imagecopymergeg ray since that
> > > > washed out my hues/saturation altogether making the image illegible
> > > > (imagecopymerge gray + imagecreate); otherwise, the colors overrode
> > > > imagecopymergeg ray (imagecopymerge gray + imagecreatetrue color).
> > > >
> > > > Using the code I borrowed I was able to change the image.. except that
> > > > it turned jet black instead!
> > > >
> > > > Has anyone ever successfully grayscaled an image using GD library? If
> > > > so, how did you do it?
> > > >
> > > > Thanx
> > > > Phil[/color][/color][/color]
Leave a comment:
-
Guest repliedRe: Grayscaling Image with GD causes image to turn jet black!
sorry, I didnt really look at the code, how is it breaking, error, not
working?
--
Mike Bradley
http://www.gzentools.com -- free online php tools
"Phil Powell" <soazine@erols. com> wrote in message
news:1cdca2a7.0 402040711.63478 c64@posting.goo gle.com...[color=blue]
> I'm sorry but that too breaks. Perhaps a code review is in order, I
> realize that imageColorsTota l($this->image) produces 0, which I am
> afraid I don't understand:
>
> class ImageGrayscaleG enerator {
>
>[/color]
/*--------------------------------------------------------------------------
----------------------------------------------------------------------------
---[color=blue]
> 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.
> --------------------------------------------------------------------------[/color]
----------------------------------------------------------------------------
-----*/[color=blue]
>
> var $image, $image_width, $image_height;
>
> // REMEMBER TO USE REFERENCE POINTER ONTO $image OBJECT TO ENSURE
> "static" CHANGE TO OBJECT AND NOT TO INSTANCE
>
> function ImageGrayscaleG enerator(&$imag e) { // CONSTRUCTOR
> $this->image =& $image;
> }
>
> function makeGray() { // VOID METHOD
> print_r($this->image); print_r("<P>");
> print_r(@imageC olorsTotal($thi s->image) . "<P>");
> for ($i = 0; $i < @imagecolorstot al($this->image); $i++) {
> $colorArray = @imageColorsFor Index($this->image, $i);
> print_r($colorA rray); print_r("<P>");
> $avg = floor(($colorAr ray['red'] + $colorArray['green'] +
> $colorArray['blue']) / 3);
> @imageColorSet( $this->image, $i, $avg, $avg, $avg);
> }
> }
> }
>
>
> Thanx
> Phil
>
> "CountScubu la" <me@scantek.hot mail.com> wrote in message[/color]
news:<_rSTb.197 24$up5.18401@ne wssvr27.news.pr odigy.com>...[color=blue][color=green]
> > Try running an average of the three colors:
> > $avg = floor( ( $color['red']) + $color['green']) + $color['blue']) ) /[/color][/color]
3 )[color=blue][color=green]
> > $R= $avg; $B = $avg; $G = $avg;
> > imageColorSet($ image_id, $a, $R, $G, $B);
> >
> >
> > --
> > Mike Bradley
> > http://www.gzentools.com -- free online php tools
> > "Phil Powell" <soazine@erols. com> wrote in message
> > news:1cdca2a7.0 402030910.a9109 fc@posting.goog le.com...[color=darkred]
> > > I borrowed this code from a source:
> > >
> > >
> > >
> > > for($a=0;$a<ima gecolorstotal ($image_id);$a+ +)
> > > {
> > > $color = imageColorsForI ndex($image_id, $i);
> > > $R=.299 * ($color['red'])+ .587 * ($color['green'])+ .114 *
> > > ($color['blue']);
> > > $G=.299 * ($color['red'])+ .587 * ($color['green'])+ .114 *
> > > ($color['blue']);
> > > $B=.299 * ($color['red'])+ .587 * ($color['green'])+ .114 *
> > > ($color['blue']);
> > > imageColorSet($ image_id, $a, $R, $G, $B);
> > > }
> > >
> > > using an image (in this case I'm using a JPEG) that is a true color
> > > image I was unable to successfully use imagecopymergeg ray since that
> > > washed out my hues/saturation altogether making the image illegible
> > > (imagecopymerge gray + imagecreate); otherwise, the colors overrode
> > > imagecopymergeg ray (imagecopymerge gray + imagecreatetrue color).
> > >
> > > Using the code I borrowed I was able to change the image.. except that
> > > it turned jet black instead!
> > >
> > > Has anyone ever successfully grayscaled an image using GD library? If
> > > so, how did you do it?
> > >
> > > Thanx
> > > Phil[/color][/color][/color]
Leave a comment:
-
Guest repliedRe: Grayscaling Image with GD causes image to turn jet black!
I'm sorry but that too breaks. Perhaps a code review is in order, I
realize that imageColorsTota l($this->image) produces 0, which I am
afraid I don't understand:
class ImageGrayscaleG enerator {
/*---------------------------------------------------------------------------------------------------------------------------------------------------------
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.
-----------------------------------------------------------------------------------------------------------------------------------------------------------*/
var $image, $image_width, $image_height;
// REMEMBER TO USE REFERENCE POINTER ONTO $image OBJECT TO ENSURE
"static" CHANGE TO OBJECT AND NOT TO INSTANCE
function ImageGrayscaleG enerator(&$imag e) { // CONSTRUCTOR
$this->image =& $image;
}
function makeGray() { // VOID METHOD
print_r($this->image); print_r("<P>");
print_r(@imageC olorsTotal($thi s->image) . "<P>");
for ($i = 0; $i < @imagecolorstot al($this->image); $i++) {
$colorArray = @imageColorsFor Index($this->image, $i);
print_r($colorA rray); print_r("<P>");
$avg = floor(($colorAr ray['red'] + $colorArray['green'] +
$colorArray['blue']) / 3);
@imageColorSet( $this->image, $i, $avg, $avg, $avg);
}
}
}
Thanx
Phil
"CountScubu la" <me@scantek.hot mail.com> wrote in message news:<_rSTb.197 24$up5.18401@ne wssvr27.news.pr odigy.com>...[color=blue]
> Try running an average of the three colors:
> $avg = floor( ( $color['red']) + $color['green']) + $color['blue']) ) / 3 )
> $R= $avg; $B = $avg; $G = $avg;
> imageColorSet($ image_id, $a, $R, $G, $B);
>
>
> --
> Mike Bradley
> http://www.gzentools.com -- free online php tools
> "Phil Powell" <soazine@erols. com> wrote in message
> news:1cdca2a7.0 402030910.a9109 fc@posting.goog le.com...[color=green]
> > I borrowed this code from a source:
> >
> >
> >
> > for($a=0;$a<ima gecolorstotal ($image_id);$a+ +)
> > {
> > $color = imageColorsForI ndex($image_id, $i);
> > $R=.299 * ($color['red'])+ .587 * ($color['green'])+ .114 *
> > ($color['blue']);
> > $G=.299 * ($color['red'])+ .587 * ($color['green'])+ .114 *
> > ($color['blue']);
> > $B=.299 * ($color['red'])+ .587 * ($color['green'])+ .114 *
> > ($color['blue']);
> > imageColorSet($ image_id, $a, $R, $G, $B);
> > }
> >
> > using an image (in this case I'm using a JPEG) that is a true color
> > image I was unable to successfully use imagecopymergeg ray since that
> > washed out my hues/saturation altogether making the image illegible
> > (imagecopymerge gray + imagecreate); otherwise, the colors overrode
> > imagecopymergeg ray (imagecopymerge gray + imagecreatetrue color).
> >
> > Using the code I borrowed I was able to change the image.. except that
> > it turned jet black instead!
> >
> > Has anyone ever successfully grayscaled an image using GD library? If
> > so, how did you do it?
> >
> > Thanx
> > Phil[/color][/color]
Leave a comment:
-
Guest repliedRe: Grayscaling Image with GD causes image to turn jet black!
Try running an average of the three colors:
$avg = floor( ( $color['red']) + $color['green']) + $color['blue']) ) / 3 )
$R= $avg; $B = $avg; $G = $avg;
imageColorSet($ image_id, $a, $R, $G, $B);
--
Mike Bradley
http://www.gzentools.com -- free online php tools
"Phil Powell" <soazine@erols. com> wrote in message
news:1cdca2a7.0 402030910.a9109 fc@posting.goog le.com...[color=blue]
> I borrowed this code from a source:
>
>
>
> for($a=0;$a<ima gecolorstotal ($image_id);$a+ +)
> {
> $color = imageColorsForI ndex($image_id, $i);
> $R=.299 * ($color['red'])+ .587 * ($color['green'])+ .114 *
> ($color['blue']);
> $G=.299 * ($color['red'])+ .587 * ($color['green'])+ .114 *
> ($color['blue']);
> $B=.299 * ($color['red'])+ .587 * ($color['green'])+ .114 *
> ($color['blue']);
> imageColorSet($ image_id, $a, $R, $G, $B);
> }
>
> using an image (in this case I'm using a JPEG) that is a true color
> image I was unable to successfully use imagecopymergeg ray since that
> washed out my hues/saturation altogether making the image illegible
> (imagecopymerge gray + imagecreate); otherwise, the colors overrode
> imagecopymergeg ray (imagecopymerge gray + imagecreatetrue color).
>
> Using the code I borrowed I was able to change the image.. except that
> it turned jet black instead!
>
> Has anyone ever successfully grayscaled an image using GD library? If
> so, how did you do it?
>
> Thanx
> Phil[/color]
Leave a comment:
-
Grayscaling Image with GD causes image to turn jet black!
I borrowed this code from a source:
for($a=0;$a<ima gecolorstotal ($image_id);$a+ +)
{
$color = imageColorsForI ndex($image_id, $i);
$R=.299 * ($color['red'])+ .587 * ($color['green'])+ .114 *
($color['blue']);
$G=.299 * ($color['red'])+ .587 * ($color['green'])+ .114 *
($color['blue']);
$B=.299 * ($color['red'])+ .587 * ($color['green'])+ .114 *
($color['blue']);
imageColorSet($ image_id, $a, $R, $G, $B);
}
using an image (in this case I'm using a JPEG) that is a true color
image I was unable to successfully use imagecopymergeg ray since that
washed out my hues/saturation altogether making the image illegible
(imagecopymerge gray + imagecreate); otherwise, the colors overrode
imagecopymergeg ray (imagecopymerge gray + imagecreatetrue color).
Using the code I borrowed I was able to change the image.. except that
it turned jet black instead!
Has anyone ever successfully grayscaled an image using GD library? If
so, how did you do it?
Thanx
Phil
Leave a comment: