not sure where but I came across as image hosting site that allows you to upload your image in a large format or to sharpen it.
I personally do not recall or know of any functions of GD library to sharpen image which might just be a different word for quality being up-ed.
If some one knows of a function to sharpen images please tell me since personally I am not aware of such functions neither in Image Magic and/or GD Library.
Thanks in advance
You can use imageconvolution in GD with a sharpen mask. From http://adamhopkinson.co.uk/blog/2010/08/26/sharpen-an-image-using-php-and-gd/:
PHP and GD can sharpen images by providing a matrix to imageconvolution:
// create the image resource from a file
$i = imagecreatefromjpeg('otter.jpg');
// define the sharpen matrix
$sharpen = array(
array(0.0, -1.0, 0.0),
array(-1.0, 5.0, -1.0),
array(0.0, -1.0, 0.0)
);
// calculate the sharpen divisor
$divisor = array_sum(array_map('array_sum', $sharpen));
// apply the matrix
imageconvolution($i, $sharpen, $divisor, 0);
// output the image
header('Content-Type: image/jpeg');
imagejpeg($i);
You'd use imageconvolution() with a matrix that corresponds to a sharpen filter. Details in this comment on the PHP site: http://php.net/manual/en/ref.image.php#56144
I haven't tried it, but this looks like what you're looking for, as far as ImageMagick goes.
In GD library of php having a file with path
lib/PHPImageWorkshop/Core/ImageWorkshopLayer.php
Please go to save public function and you can change the imageQuality upto 100.
make sure which type of image you want to create.
Hope this will help you.
Related
Let's suppose I want to create a face generator, where I would design several pictures for face form, ears, noses, mouth, hair. Given a combination of those pictures how can I create a new picture in PHP? For instance, a simplified version:
There is face1.png, face2.png, nose1.png and nose2.png. How could I programmatically merge face1.png with nose2.png, so the result picture would hold content from both picture?
You've basically got three options: GD, Cairo or ImageMagic. I'd recommend using the Imagick class if it's available. If not, ImageMagick through PHP system calls. If that's not available, GD will probably suffice.
It depends on your server configuration, which of these are available and which would require additional packages to be installed.
There's a very simple example in the Imagick documentation of combining images: https://secure.php.net/manual/en/imagick.compositeimage.php
I also found this example for GD:
Merge two PNG images with PHP GD library
There is a function named imagecopy. This function overrides a part of the destination image using a source image. The given part is specified as parameters. Before you tell me that this does not solve your problem, I have to add that the pixels in the destination picture will not be overriden by the pixels of the source picture if the pixels are transparent. You need to use imagealphablending and imagesavealpha on the source picture, like this:
public static function experimental($images, $width, $height, $dest = null) {
$index = 0;
if ($dest === null) {
$dest = $images[$index++];
}
while ($index < count($images)) {
imagealphablending($images[$index], true);
imagesavealpha($images[$index], true );
imagecopy($dest, $images[$index++], 0, 0, 0, 0, $width, $height);
}
return $dest;
}
If we have these two pictures:
The result will be this:
You really want make it with PHP?
Ok.
1) You can use GD library for image processing.
2) You can use imagemagic PHP wrapper -- imagic.
But I think you should use canvas on client side. And for saving result you can send base64 png image representation of canvas (or separated layers/pictures) to backend.
I have a website where users have been uploading a bunch of high quality PNG files. I want to use PHP to convert them to JPEG and re-size them to make them smaller in file size.
How can I do this when they upload the file? What is the process for doing this? Is a new image created or is it edited?
Thanks
You can use something like this :
function pngTojpg($pngImage, $outputPngFile, $outputJpgFile, $quality) {
$image = imagecreatefrompng($pngImage);
//Save the png image
imagepng($image, $outputPngFile);
//Save the jpeg image
imagejpeg($image, $outputJpgFile, $quality);
// Free up memory
imagedestroy($image);
}
"quality is optional, and ranges from 0 (worst quality, smaller file) to 100 (best quality, biggest file). The default is the default IJG quality value (about 75)"
The php doc : imagejpeg, imagecreatefrompng
These functions are from the GD library, here the installation instruction : Php GD
Use ImageMagick to do all kinds of conversions. You should be able to find examples at this link:
http://www.php.net/manual/en/book.imagick.php
Just try ImageMagick:
http://www.imagemagick.org/script/convert.php
I think, that is what you are looking for.
Well, you can use simple php code to do that but I use and recomend this library to work with images:
Verot - Class Upload http://www.verot.net/php_class_upload.htm
You can convert images to other format, reduce size, transform and do a lot others stuffs.
I was doing some image editing with PHP, since GD provides less functionalities, I switched to Imagick.
One of the processes is to greyscale images. Everything went fine (locally on Windows 7, Imagick 2.2.1-dev 6.5.8-7 Q16) till I uploaded the script to my web hosting server (Linux, Imagick 3.0.1, 6.2.8, 2010-10-20, Q16).
I'v tried to change the quality, but it didn't improve anything.
$img->setImageCompression(imagick::COMPRESSION_JPEG);
$img->setImageCompressionQuality(100);
Here is the results from GD, Imagick and Photoshop
I believe something's wrong with version 3.0.1. Can someone please confirm that?
Q1: Is there an alternative way to convert an image to greyscale with Imagick?
Q2: Is it possible to convert a GD resource to Imagick? So I can use imagefilter($img, IMG_FILTER_GRAYSCALE); to get the correct result and then output with Imagick.
ps: For Q2, you might suggest me to just use GD to process the image. But the problem is that imagejpeg() cannot save images with resolution preserved. and that is actually the reason I switched to Imagick.
This is my preferred way to make a B&W photo in php/imagick: $im = $im->fxImage('intensity');
That applies a function to the image, where intensity is equal to 0.299*red+0.587*green+0.114*blue.
That formula is based on how our eyes are more sensitive to different colours, and as such the difference between that and a "flat" grayscale image really is night and day.
More details here:
http://php.net/manual/en/imagick.fximage.php
http://www.imagemagick.org/script/fx.php
function ImagickToGD($imagick){
$tmpfile = tmpfile();
$imagick->writeImage($tmpfile);
return imagecreatefromstring(file_get_contents($tmpfile));
}
Note that this function does not do any cleanup (except the temp file, which PHP cleans automatically).
So, for example, your code should look like:
$img = new Imagick();
// ...
$gd = ImagickToGD($img);
unset($img); // destroy imagick
imagefilter($gd, IMG_FILTER_GRAYSCALE);
imagejpeg($gd, $target_name, 100);
imagedestroy($gd);
Also, I did not understand the part about "preserving resolution". There is nothing in these operations relating to resolution. My guess is you meant compression? If you want full quality (ie, no compression) simply use 100 as compression value (as I did).
This results in maintaining the existing quality, since opening an image of 70% quality and saving it back with 70% quality actually decreases the final quality by 49% (70% of 70%).
function GDToImagickTo($gd){
$tmpfile = tmpfile();
imagepng($tmpfile); // Png is our best image deal:
// lossless compression, transparency etc..
$imagick = new Imagick()
$imagick->readImage($tmpfile);
return $imagick;
}
Refer this website and check out the image Magick operators found here www.rubblewebs.co.uk/imagemagick/
Also go with www.fmwconcepts.com/imagemagick/ you will find some examples out here...
You can use the image class what you prefer and then use the method readImageBlob to send it to the imagick http://www.php.net/manual/en/imagick.readimageblob.php
I am looking to add a background to images that users upload that are not square. So if they upload a tall and skinny photo I want to add a white background to the sides of the image to make the resulting image have an aspect ratio of 1:1. Is this possible using PHP or javascript?
You can use the GD library for what, with a library called Wideimage it's a breeze:
$image = WideImage::load('img_form_field_name');
$size = max($image->getHeight(), $image->getWidth());
$white = $image->allocateColor(255, 255, 255);
$image->resizeCanvas($size, $size, 'center', 'center', $white);
See the documentation and examples, many functions can even be tested interactively.
The GD library is the most commonly used image manipulation package. It's a set of functions often installed with PHP which handle image manipulation.
What you'll want to do is either scale and crop your image to a specific aspect ratio so that you place your image on a square canvas and cut off whatever does fit or
You'll want to simply resize your image to a fixed aspect ratio and place it on a square canvas with whitespace around it.
Either way, this tutorial should point you in the right direction
http://return-true.com/2009/02/making-cropping-thumbnails-square-using-php-gd/
Yep you'll want to look into either the GD library or ImageMagik. There are plenty of tutorials available for this task.
Functions like imagecreatetruecolor() etc will allow you to create a new image, and then stack the uploaded image on top of it and save it as a new file.
Yes.
http://www.php.net/manual/en/refs.utilspec.image.php
Is it possible to take this image:
And apply this mask:
And turn it into this:
Using either GD or Imagick? I know it's possible to mask an image using shapes but I'm not sure how to go on about doing it with a pre-created alphatransparent image. :s
Using Imagick and ImageMagick version > 6 (I don't know if it will work on older versions):
// Set image path
$path = '/path/to/your/images/';
// Create new objects from png's
$dude = new Imagick($path . 'dude.png');
$mask = new Imagick($path . 'dudemask.png');
// IMPORTANT! Must activate the opacity channel
// See: http://www.php.net/manual/en/function.imagick-setimagematte.php
$dude->setImageMatte(1);
// Create composite of two images using DSTIN
// See: http://www.imagemagick.org/Usage/compose/#dstin
$dude->compositeImage($mask, Imagick::COMPOSITE_DSTIN, 0, 0);
// Write image to a file.
$dude->writeImage($path . 'newimage.png');
// And/or output image directly to browser
header("Content-Type: image/png");
echo $dude;
I think you are looking for imagealphablending. I use it for watermarks, and I believe it will do the effect you are looking for.
Great work with (ImageMagick) NOT GD .. I see the tags of this question is GD!!
Here is a GD version at this link:
PHP GD Use one image to mask another image, including transparency