I have used PHP-Imagick to create a patterned-image of repeated circles, like the given example-image above. Below is the code that created the image above. I have explicitly commented the code and the variable names are kept pretty verbose in order to know whats going on.
$canvas = new Imagick();
$cw = 700; // user provided width
$ch = 300; //user provided height
$hrzntl_c = 10; //user provided - number of horizontal circles - min 2 and max 200
$c_diamtr = $cw / $hrzntl_c; //set the diameter of circle
$c_radius = $c_diamtr /2; //set the radius of circle
$vrtcl_c = $ch / $c_diamtr; //calculated number of vertical circles.
$canvas->newImage( $cw, $ch, new ImagickPixel( "seagreen" ) ); //create a canvas
$draw = new ImagickDraw(); // create a draw object
$draw->setFillColor( new ImagickPixel( "white" ) ); // set the fill color
for ($i = 0; $i <= $hrzntl_c; $i++){ //loop horizontal
for ($j = 0; $j <= $vrtcl_c; $j++){ //loop vertical
$draw->ellipse( $c_radius + $c_diamtr * $i, $c_radius + $c_diamtr * $j, $c_radius, $c_radius, 0, 360 );
}
}
$canvas->drawImage( $draw ); // render the circles to the canvas
$canvas->setImageFormat( "png" ); // set the image format to png
header("Content-Type: image/png"); // Output the image
echo $canvas;
ISSUE : Now you have got an idea that the circles are designed to be horizontally justified. I need help to justify the vertical circles as well. Look at the bottom of the example image and you can see that circles are indeed not justified. By "justified", I mean if you see a half/full circle towards top then you should see half/full a circle at the bottom too. Like this perfect example.
Calculate an offset based on the image height and the circle count. Btw, you should adapt your count calculation:
$vrtcl_c = ceil($ch / $c_diamtr);
$verticalOffset = ($ch - $vrtcl_c * c_diamtr) / 2;
Then, shift your drawings:
for ($j = 0; $j < $vrtcl_c; $j++){ //loop vertical
$draw->ellipse( $c_radius + $c_diamtr * $i,
$c_radius + $c_diamtr * $j + $verticalOffset,
$c_radius, $c_radius, 0, 360 );
}
The basic question: Is it possible to determine the height of a MultiCell before placing it in the document?
The reason: I've been tasked with creating a PDF version of a form. This form allows text input, with a resulting variable length. One person my not enter anything, another person may write a few paragraphs. "The Powers That Be" do not want this text breaking between pages.
Currently, after placing each block, I check the position on the page, and if I'm near the end, I create a new page.
if($this->getY() >= 250) {
$this->AddPage('P');
}
For the most part, this works. But there are the few sneaky ones that come in at, say 249, and then have boatloads of text. It seems it would make more sense to determine the height of a block before placing it to see if it actually fits on the page.
Surely there must be a way to do this, but Googling around hasn't proven very helpful.
Edit to clarify: The PDF is being generated after the form is submitted. Not an active, editable PDF form...
Earned the tumbleweed badge for this question. :( Anyway, in the off chance someone has the same issue, I figured I'd answer with what I did. I doubt this is the most efficient method, but it got the job done.
First, I create two FPDF objects; a temporary one that never gets output and the final, complete pdf that the end user will see.
I get my current Y coordinate in both objects. I then place the block of data using Cell() or MultiCell() (for this form, usually a combination of the two) into the temporary object, and then check the new Y coordinate. I can then do the math to determine the height of the block. -Note, the math can get a bit funky if the block breaks across pages. Remember to take your top and bottom margins into account.
Now that I know the height of a block, I can take the current Y coordinate of the destination object, subtract it from the total height of a page(minus bottom margin) to get my available space. If the block fits, place it, if not, add a page and place it at the top.
Repeat with each block.
Only caveat I see is if any single block is longer then an entire page, but with this form, that never happens. (famous last words...)
See also https://gist.github.com/johnballantyne/4089627
function GetMultiCellHeight($w, $h, $txt, $border=null, $align='J') {
// Calculate MultiCell with automatic or explicit line breaks height
// $border is un-used, but I kept it in the parameters to keep the call
// to this function consistent with MultiCell()
$cw = &$this->CurrentFont['cw'];
if($w==0)
$w = $this->w-$this->rMargin-$this->x;
$wmax = ($w-2*$this->cMargin)*1000/$this->FontSize;
$s = str_replace("\r",'',$txt);
$nb = strlen($s);
if($nb>0 && $s[$nb-1]=="\n")
$nb--;
$sep = -1;
$i = 0;
$j = 0;
$l = 0;
$ns = 0;
$height = 0;
while($i<$nb)
{
// Get next character
$c = $s[$i];
if($c=="\n")
{
// Explicit line break
if($this->ws>0)
{
$this->ws = 0;
$this->_out('0 Tw');
}
//Increase Height
$height += $h;
$i++;
$sep = -1;
$j = $i;
$l = 0;
$ns = 0;
continue;
}
if($c==' ')
{
$sep = $i;
$ls = $l;
$ns++;
}
$l += $cw[$c];
if($l>$wmax)
{
// Automatic line break
if($sep==-1)
{
if($i==$j)
$i++;
if($this->ws>0)
{
$this->ws = 0;
$this->_out('0 Tw');
}
//Increase Height
$height += $h;
}
else
{
if($align=='J')
{
$this->ws = ($ns>1) ? ($wmax-$ls)/1000*$this->FontSize/($ns-1) : 0;
$this->_out(sprintf('%.3F Tw',$this->ws*$this->k));
}
//Increase Height
$height += $h;
$i = $sep+1;
}
$sep = -1;
$j = $i;
$l = 0;
$ns = 0;
}
else
$i++;
}
// Last chunk
if($this->ws>0)
{
$this->ws = 0;
$this->_out('0 Tw');
}
//Increase Height
$height += $h;
return $height;
}
In addition to JLuc answer which is working as one would imagine it, too. Implementing this functionality however is not trivial and requires you to extend the main fpdf class.
First off if you have an extended fpdf already you could just copy JLuc's answer and skip this step. If not, go ahead like this:
create a File and Class that extends FPDF (name the file as your class name):
<?php
namespace YourNameSpace\Library;
class FpdfExtended extends \FPDF {
...
}
If you are not using namespaces you could just use require. Once that file is created insert the GetMultiCellHeight from the gist or this answer.
Now you'd need to instantiate the extended Class a simple constructor most likely suffices.
use YourNameSpace\Library\FpdfExtended
...
$pdf = new FpdfExtended();
...
now you could simply use the GetMultiCellHeight method to decide the next cells height like so:
$col1 = 'col 1 text without line break';
$col2 = 'col 2 text with line break \n and some more text';
// get next cell height
$nextHeight = $pdf->GetMultiCellHeight($width, $height, $col2);
$pdf->MultiCell($width, $nextHeight, $col1, 0, 'L', 1);
Good luck and happy coding you poor souls still using FPDF.
I have done it by this way. We are passing height in multicell. That is $h. Total height would be (number of lines * $h). Because $h is height of one line. And we want to know total height so total height is $totalLines * $h.
I have a PNG frame and I want to know its thickness. I am able to calculate the width/height of the image itself.
$frame = imagecreatefrompng('frame.png');
// get frame dimentions
$frame_width = imagesx($frame);
$frame_height = imagesy($frame);
But can't figure out a way to calculate thickness of frame, please see image below so see what I mean.
Any suggestions?
From the last answer it shows that there's no objects in a raster image file. However, you can do it by searching the first occurrence of transparent colour and the first occurrence of the non-transparent colour and calculate the distance of them (assumes that your image's blank area are all transparent).
Example code:
<?php
$img = imagecreatefrompng('./frame.png');//open the image
$w = imagesx($img);//the width
$h = imagesy($img);//the height
$nonTransparentPos = null;//the first non-transparent pixel's position
$transparentPos = null;//the first transparent pixel's position
//loop through each pixel
for($x = 0; $x < $w; $x++){
for($y = 0; $y < $h; $y++){
$color = imagecolorsforindex($img,imagecolorat($img,$x,$y));
if($color['alpha'] < 127 && $nonTransparentPos === null){
$nonTransparentPos = array($x,$y);
}
if($color['alpha'] === 127 && $transparentPos === null){
$transparentPos = array($x,$y);
}
}
//leave the loop if we have finished finding the two values.
if($transparentPos !== null && $nonTransparentPos !== null){
break;
}
}
$length = $transparentPos[0]-$nonTransparentPos[0];//calculate the two point's x-axis distance
echo $length;
?>
There aren't any objects in a PNG file. You can only get a color (with a transparency) by coordinates with imagecolorat() & imagecolorsforindex().
I'm trying to figure out a script that will generate a texture (which can then be multiplied by a grayscale image to "apply" it). So far my method involves seeding the RNG, then randomly generating a 8x8 matrix of integers in the range [0,3], then scaling up that matrix to a 256x256 image using some level of interpolation.
Here's an example output (seed value 24):
(source: adamhaskell.net)
On the left is the matrix scaled with nearest-neighbor interpolation. On the right is my attempt at bilinear interpolation. For the most part it seems okay, but then you get structures like near the middle-left where there are two diagonally-adjoining orange squares faced with two diagonally-adjoining red squares, andthe result is no interpolation for that area. Additionally, it's being treated more like a heatmap (as shown by the abundance of orange in the top-left corner) and that's causing more problems.
Here's the code I have for my "bilinear interpolation":
<?php
$matrix = Array();
srand(24);
$dim = 256;
$scale = 32;
for($y=0;$y<=$dim/$scale;$y++) for($x=0;$x<=$dim/$scale;$x++) $matrix[$y][$x] = rand(0,3);
$img = imagecreate($dim,$dim);
imagecolorallocate($img,255,255,255);
$cols = Array(
imagecolorallocate($img,128,0,0),
imagecolorallocate($img,128,64,32),
imagecolorallocate($img,128,128,0),
imagecolorallocate($img,64,64,64)
);
for($y=0;$y<$dim;$y++) {
for($x=0;$x<$dim;$x++) {
$xx = floor($x/$scale); $yy = floor($y/$scale);
$x2 = $x%$scale; $y2 = $y%$scale;
$col = $cols[round((
$matrix[$yy][$xx]*($scale-$x2)*($scale-$y2)
+ $matrix[$yy][$xx+1]*$x2*($scale-$y2)
+ $matrix[$yy+1][$xx]*($scale-$x2)*$y2
+ $matrix[$yy+1][$xx+1]*$x2*$y2
)/($scale*$scale))];
imagesetpixel($img,$x,$y,$col);
}
}
header("Content-Type: image/png");
imagepng($img);
exit;
In reality, this may be a bit of an XY Problem. What I'm specifically trying to do is generate "fur patterns" for creatures in a game I'm planning. In particular I want to be able to have it so that breeding mixes elements from the two parents (be it colour or elements of the pattern), so just having a random seed won't really cut it. Ideally I need some kind of vector-based approach, but I'm way out of my depth there so any help would be very much appreciated.
A couple things come to mind:
You are not interpolating the color values. To expand on zakinster's comment, you are interpolating the color indices, and then rounding to the nearest one. One effect of this is that you wind up with a swath of yellow (index 2) in between orange (index 1) and gray (index 3) areas. If you interpolated the color values instead, you would wind up with, perhaps, grayish orange?
You have more yellow and orange, and less red and gray in the final image. This is because of using round() to snap to a color index. Your calculation (before round()) may produce floats evenly distributed between 0 to 3, but rounding doesn't preserve it.
So, here are some suggestions:
If you are not limited to 4 colors, use more. Interpolate the color values (i.e. (128,0,0) mixed with (64,64,64) produces (91,32,32)) rather than the indices.
If you are limited to just those 4 colors, try some kind of dithering. A simple approach, with minimal changes to your code, would be to add some randomness to the color index that is chosen. So, instead of round(...), do something like this: say your calculation produces the value 1.7. Then, round to up to 2 with a 70% probability, and down to 1 the other 30%. This will blend the colors, but it may produce a very noisy image. If you are prepared to change your code more substantially, check out Floyd-Steinberg dithering.
I know it is old question, and answer from #markku-k is correct, anyway I have similar problem and here is my modified code for the question
several notices:
it produces 2 images in one, to show "original matrix" and result
it uses 8x8 matrix to produce result, but actual matrix is 10x10 to cover borders
it uses color to color index algorithm base on simple delta, it works ok for me
here is the code:
<?php
$matrix = array();
$dim = 256;
$scale = 32;
for($y=0; $y<=9; $y++)
{
$matrix[$y] = array();
for($x=0; $x<=9; $x++)
{
$same = false;
do
{
$matrix[$y][$x] = mt_rand(0, 3); // do not use rand function, mt_rand provide better results
if ( ($x>0) && ($y>0) ) // check for checkers siatuion, where no colors are preferable and produce 90 degree angles
{
$c1 = $matrix[$y-1][$x-1];
$c2 = $matrix[$y][$x];
$c3 = $matrix[$y-1][$x];
$c4 = $matrix[$y][$x-1];
$same = ( ($c1==$c2) && ($c3==$c4) );
}
} while ($same);
}
}
$img = imagecreate($dim*2 + 32*4, $dim + 32*2);
$colorsRGB = array(0x800000, 0x804020, 0x808000, 0x404040);
$cols = Array(
imagecolorallocate($img,128,0,0), // red
imagecolorallocate($img,128,64,32), // orange
imagecolorallocate($img,128,128,0), // yellow
imagecolorallocate($img,64,64,64), // gray
imagecolorallocate($img,0,0,0), // black, just to fill background
);
imagefilledrectangle($img, 0, 0, $dim*2 + 32*4 - 1, $dim + 32*2 - 1, $cols[4]);
function mulclr($color, $multiplicator)
{
return array(($color>>16) * $multiplicator, (($color>>8)&0xff) * $multiplicator, ($color&0xff) * $multiplicator);
}
function addclr($colorArray1, $colorArray2)
{
return array($colorArray1[0]+$colorArray2[0], $colorArray1[1]+$colorArray2[1], $colorArray1[2]+$colorArray2[2]);
}
function divclr($colorArray, $div)
{
return array($colorArray[0] / $div, $colorArray[1] / $div, $colorArray[2] / $div);
}
function findclridx($colorArray, $usedColors)
{
global $colorsRGB;
$minidx = $usedColors[0];
$mindelta = 255*3;
foreach ($colorsRGB as $idx => $rgb)
{
if (in_array($idx, $usedColors))
{
$delta = abs($colorArray[0] - ($rgb>>16)) + abs($colorArray[1] - (($rgb>>8)&0xff)) + abs($colorArray[2] - ($rgb&0xff));
if ($delta < $mindelta)
{
$minidx = $idx;
$mindelta = $delta;
}
}
}
return $minidx;
}
for($y=0; $y<($dim+64); $y++)
{
for($x=0; $x<($dim+64); $x++)
{
$xx = $x>>5;
$yy = $y>>5;
$x2 = ($x - ($xx<<5));
$y2 = ($y - ($yy<<5));
imagesetpixel($img, $x, $y, $cols[$matrix[$yy][$xx]]);
if ( ($xx>0) && ($yy>0) && ($xx<=8) && ($yy<=8) )
{
$color1 = $colorsRGB[$matrix[$yy][$xx]];
$color2 = $colorsRGB[$matrix[$yy][ ($xx+1) ]];
$color3 = $colorsRGB[$matrix[ ($yy+1) ][$xx]];
$color4 = $colorsRGB[$matrix[ ($yy+1) ][ ($xx+1) ]];
$usedColors = array_unique(array($matrix[$yy][$xx], $matrix[$yy][ ($xx+1) ], $matrix[ ($yy+1) ][$xx], $matrix[ ($yy+1) ][ ($xx+1) ]));
$a1 = mulclr($color1, ($scale-$x2)*($scale-$y2));
$a1 = addclr($a1, mulclr($color2, $x2*($scale-$y2)));
$a1 = addclr($a1, mulclr($color3, ($scale-$x2)*$y2));
$a1 = addclr($a1, mulclr($color4, $x2*$y2));
$a1 = divclr($a1, $scale*$scale);
$clrIdx = findclridx($a1, $usedColors);
$col = $cols[$clrIdx];
imagesetpixel($img, $dim+$x+32*2, $y, $col);
}
}
}
header("Content-Type: image/png");
imagepng($img);
exit;
here is sample result:
I've looked around on SO but I couldn't find any similar question.
After opening an image in PHP I'm willing to check every pixel, and, if their red + green values is lower than 150 I would turn that pixel to white, instead if the sum is higher than 150 I would turn that pixel to black.
Is this possible?
I've tried with imagefilter() but I can't make it work as expected. Maybe there are more appropriate functions to use.
something like
$image = imagecreatefrompng($img);
$xdim = imagesx($image);
$ydim = imagesy($image);
for ($x = 1; $x <= $xdim-1; $x++) {
for ($y = 1; $y <= $ydim-1; $y++) {
$rgb = imagecolorat($image, $x, $y);
if($rgb>150)
$color = 0x00;
else
$color = 0xFF;
}
}
Look at using the imagecolorat function (I think it may be part of the GD library). You can get the RGB from that. Then use imagecolorset to set the new RGB.