PECL Imagick adaptiveSharpenImage not working? - php

I'm trying to sharpen my images using this function, but it's not working. Whatever values I pass in for radius and sigma I get an identical image (same file size even) out.
It returns a 1 suggesting no error. What might be going wrong here?
$photo = new Imagick(PHOTOS_DIR.$sFilename);
$photo->adaptiveSharpenImage(2,1); //4,2 ... 0,10, 0.5,0.5 - all give identical results
$guid = md5(uniqid(rand(),true));
$photo->writeImage(PHOTOS_DIR.'/temp/'.$guid.'.jpg');
I tried passing in imagick::CHANNEL_BLUE for the optional third parameter, it made no difference.
CentOS 6.5
PHP 5.5.12
pecl-imagick 3.1.2
imagemagick 6.5.4

The adaptiveImageSharpen function is really subtle in some circumstances. The images below are the source and then the sharpened one produced by:
$radius = 10;
$sigma = 2;
$imagick->adaptiveSharpenImage($radius, $sigma);
Source image
Sharpened image
Even at those relatively large values, the image is definitely sharpened but the effect is only noticeable when compared to the source image. The radius you choose will depend on the size of your source image, but ought to be at least a couple of pixels across. Alternatively you can set a radius of zero, and ImageMagick should choose an appropriate value for the image.
Depending on what you're trying to achieve with the sharpening you may be better off with and old fashioned unsharpMaskImage if adaptiveSharpenImage is always too subtle an effect for you.
Or it could just be broken on the very old version of ImageMagick you're using - can you try with the sample image and settings above.

Related

Remove whitespace using Imagick and PHP, then save as transparent PNG

I've got an image and want to remove all whitespace around it, and then save it as a transparent PNG. I'm using Imagick in PHP to do so, but my script doesn't seem to function properly.
<?php
$im = new Imagick("http://images.icecat.biz/img/norm/high/14688888-2862.jpg");
$im->borderImage("#ffffff", 20, 20);
$im->trimImage(0.3);
$im->setImagePage($im->getImageWidth(), $im->getImageHeight(), 0, 0);
$im->setImageFormat("png");
header("Content-Type: image/" . $im->getImageFormat());
echo $im->getImageBlob();
?>
What do I need to do to remove all white (and close to white) areas at the borders? And when that is done, can I easily resize the image to crop all of the transparency?
The fuzz factor needs to be a quantum scaled value, not just for this function but almost all functions that take 'fuzz' as a parameter.
i.e. you need to scale it up to the quantum range.
$im->trimImage(0.3 * \Imagick::getQuantum());
Or if you are using an earlier version of Imagick that doesn't have that method, then instead do:
$range = $image->getQuantumRange();
$image->trimImage(0.3 * $range['quantumRangeLong']);
The reason for this is to allow precise control over the pixel matching. If the value was passed in as a float value in the range 0-1 it would not possible to have exact control over the value that was used for matching.
By instead using an integer value (for versions of Imagick that do not have HDRI enabled) it allows you to precisely control the values that are compared for the operation.
You need something like an autocrop based on pixel values, I think this will help:
http://www.imagemagick.org/script/command-line-options.php#trim
you might also like:
http://fmwconcepts.com/imagemagick/autotrim/index.php
source:
http://www.imagemagick.org/discourse-server/viewtopic.php?t=10843

Imagemagick resizing control quality and extension

I am trying to learn Imagemagick, php.net docs are terrible T_T, and I cannot seem to find any answers to my questions. I am wanting to allow people to upload images then resize them and lose EXIF data.
Heres what I have currently.
$thumbnail = new Imagick("http://4.bp.blogspot.com/-hsypkqxCH6g/UGHEHIH43sI/AAAAAAAADGE/0JBu9izewQs/s1600/luna-llena1.jpg");
$thumbnail->thumbnailImage( 100, 100, true );
$thumbnail->writeImage( "avatar/thumbnail.jpg" );
Now how do I control the image file that it is being saved as? Lets say the user submits a gif/png/jpg how would I go about taking that image then saving it as the same input format or changing them all to .png?
This IMO produces the best results for imagick thumbnails;
Load the picture
$img = new imagick( $_FILES['Picture']['tmp_name'] );
Trim an excess off the picture
$img->trimImage(0);
Create the thumbnail, in this case, I'm using 'cropThumbnailImage'
$img->cropThumbnailImage( 180, 180 );
Set the format so all pics can now be the same standard format
$img->setImageFormat( 'jpeg' );
Set the Image compression to that of a jpg
$img->setImageCompression(Imagick::COMPRESSION_JPEG);
Set the quality to be 100
$img->setImageCompressionQuality(100);
The resulting thumbnail is then a little bit blury IMO, so I add a slight sharpening effect to make it 'sharper'. . play around with these settings, but I like..
$img->unsharpMaskImage(0.5 , 1 , 1 , 0.05);
I agree, the PHP.net docs are not very helpful. I've found that it's easiest to find how to do things using commands, then match the commands up with the PHP methods. I'm a little late replying so you might have figured it out by now, but if not, or for the benefit of anyone else:
If you want to change the image format before saving, add this before your writeImage line:
$thumbnail->setImageFormat('png');
Then change the extension in your writeImage line to match, e.g. thumbnail.png
To change the quality, write:
$thumbnail->setImageCompressionQuality(40); // Adjust the number 40
In some cases you might also want to set the compression type by writing:
$thumbnail->setImageCompression(Imagick::COMPRESSION_JPEG);
You can find the COMPRESSION constants here: http://www.php.net/manual/en/imagick.constants.php
Note: These are just examples. This compression would not actually work with a png file.

Add round corners to a jpeg file

I am trying to add round corners to a jpeg file, but the problem is that after adding round corners, I am getting a black background color. Somehow I am not able to change it to any other color (white, transparent, red). It just simply shows black background where the image has rounded corners.
The code that I am using is:
<?php
$image = new Imagick('example.jpg');
$image->setBackgroundColor("red");
$image->setImageFormat("jpg");
$image->roundCorners(575,575);
$image->writeImage("rounded.jpg");
header('Content-type: image/jpeg');
echo $image;
?>
I cannot use png as the jpeg files are huge, about 5 MB, so if I used png, the file size would go up to 26 MB, even though the png adds transparent round corners.
Also the IMagick version that i am using is:
ImageMagick 6.6.2-10 2010-06-29 Q16 http://www.imagemagick.org
Also the output(image generated) will get printed so I don't know if css will work over here.
Sorry, I am trying to actually create a new jpeg file with rounded corners from an already existing jpeg file that doesn't have round corners this is actually a photograph taken from a camera, so there are multiple/too many colors so I can't use gif as well.
Also my site will only just generate the round corner image then afterwards it will get downloaded using a FTP program by the admin of the site and then using a system software will get printed, so in short my website will not be printing the image but rather just generate it
Try this:
<?php
$input = 'example.jpg';
$size = getimagesize($input);
$background = new Imagick();
$background->newImage($size[0], $size[1], new ImagickPixel('red'));
$image = new Imagick($input);
$image->setImageFormat("png");
$image->roundCorners(575,575);
$image->compositeImage($background, imagick::COMPOSITE_DSTATOP, 0, 0);
$image->writeImage("rounded.jpg");
?>
I may get downvoted, but I say let css deal with the corners and take some load off of your server :)
CSS rounded corners.
JPG doesn't have a transparent color(s) (alpha channels) in its palette.
The output image must use either PNG or GIF (or another image format that supports alpha channels).
setImageBackgroundColor is another option if you want an opaque background.
EDIT
Your comment reminds me that you could try to use the command line; shell_exec() will run a command line argument from PHP. The command in the ImageMagick API you'll need to start with is convert example.jpg, and then you can pass flags with the various parameters you want.
Since ImageMagick is already installed, it will work right away. You may need to point your system PATH to the ImageMagick directory where all of the executables are.
There's plenty of questions and forums dedicated to rounded corners with this method so I'll leave that up to you.
Here's a helpful tip though - there is a silly confusion with the convert command, since Windows also has a convert.exe that is rarely used, but will confuse your command line, so make sure you're calling the right convert. ;) To test if it's working, try convert example.jpg example.gif (which should convert your example to a gif).
To get output from your command line, finish all commands with 2>&1 which will pipe cmd output back into PHP.

php imagerotate() ruins alpha on png?

I've been bashing my head agains something simple..
// ....all prev code is fine....
$pasteboard =imagecreatetruecolor($imgs['bg']["width"],$imgs['bg']["height"]);
imagealphablending($pasteboard, false);
imagecopyresampled($pasteboard, $imgs['bg']["img"],0,0,0,0,$imgs['bg']["width"],$imgs['bg']["width"],imagesx($imgs['bg']["img"]),imagesy($imgs['bg']["img"]));
imagecopyresampled($pasteboard, $imgs['photo']["img"],20,20,0,0,$imgs['photo']["width"],$imgs['photo']["width"],imagesx($imgs['photo']["img"]),imagesy($imgs['photo']["img"]));
imagesavealpha($pasteboard,true);
//send it out
$out = $pasteboard;
header('Content-type: image/png');
imagepng($out);
//then garbage collection
gives me this:
HORAY!
perfect alpha png composite...
Now I want to rotate it, so instead of the $out=$pasteboard i do this:
imagesavealpha($pasteboard,true);
//rotate it
$out = imagerotate($pasteboard,5,imagecolorexactalpha($pasteboard,255,255,255,50),0);
header('Content-type: image/png');
imagepng($out);
which sadly gives me this:
BOOOO!
Ive tried setting the color like:
imagerotate($pasteboard,5,0x00000000,0);
also the last attr like:
imagerotate($pasteboard,5,0x00000000,1);
new empty images sampled etc etc...
no dice....
Can anyone help?
I'm answering my question simply because I've tried 10-15 suggestions i've seen allover the web all of which offering 'nearly' right solutions but nothing exact, Also I've seen this question posted a few places now, and hopefully if anyone reaches this page in future it would be best to show the solution as the direct answer.
MASSIVE thanks to #cristobal for the help and efforts, if I could vote you up any more I would !
The knack seems to be:
//rotate it
$pasteboard = imagerotate($pasteboard,5,0XFFFFFF00,0); //<-- here must be RRGGBBAA, also last attr set to 0
imagesavealpha($pasteboard, true); // <-- then to save it... dont ask me why..
//send it out
header('Content-type: image/png');
imagepng($pasteboard);
produces this (it has a perfect alpha even though you cant see against the white page):
REALLY not the most fun 5 hrs of my life... hopefully it will stop someone else going through the same pain..
Using the same code above and using a blue color for the third parameter in the imagerotate operation, which will be it used to fill the uncovered zone after the rotation i.e.:
imagerotate($pasteboard, 5, 255);
We get the following image
we see the blue area is the uncovered zone which it fills, while the black color is the to be the border shadow from the image which GD does not seem to handle well along the interpolation used in the rotation.
The same image rotated using the convert for imagemagick. commmand i.e. $> convert -rotate 5 image.png image_rotated.png results in the image below
Clearly GD does not handle alpha colors well when rotating.
If you have access to use the convert commmand using exec or process, you should pipe those image operation to imagemagick instead. GD is a simple image library which has not been updated much the latest years. Otherwise try Imagemagick, Cairo or Gmagick which there are pecl plugins for too http://php.net/manual/en/book.image.php.
Last resort somebody made a function that which uses GD http://www.exorithm.com/algorithm/view/rotate_image_alpha for what you are looking after but the result is not pretty since its a simple linear interpolation:
taken from How to rotate an image in GD Image Library while keeping transparency?. Perhaps if you convert the linear interpolation function to a Bicubic or Quad it will look better.
Note these answers did not work for me but this did.
$destimg = imagecreatefromjpeg("image.png");
$rotatedImage = imagerotate($destimg, 200, 0);
imagesavealpha($rotatedImage, true);
imagepng($rotatedImage,"rotated.png");

PHP imagick detect transparency

I want to be able to detect whether an image is transparent or not using the Imagick PHP extension.
So far, the only luck I've been having is to run the exec() / some other command, and use the ImageMagick command line tool to achieve this. Here's what I mean:
exec("identify -verbose example_transparent_image.png | grep \"Alpha\"", $output);
$is_transparent = !empty($output) ? true : false;
The logic is simple. Do a verbose check on the image in question: if the output contains any alpha information, that means it uses transparency.
It seems that the PHP imagick extension should have this as one of its commands, but the lack of documentation is killing me. It seems silly to have to run this kind of check each time.
Ahhh, solved (I think). Imagick has a function getImageAlphaChannel() which returns true if it contains any alpha information and false if it doesn't.
Make sure you have ImageMagick 6.4.0 or newer.
http://www.php.net/manual/en/function.imagick-getimagealphachannel.php
Maybe this
http://ru.php.net/manual/en/function.imagick-identifyimage.php
What's about this?
substr((new Imagick($FILE))->identifyImage()['type'], 0, -5) == 'Alpha'
look at the documentation of identifyImage. You will notice the missing documentation of the functions output. It's just a parsed version of
identify -verbose $FILE (from the imagick package)
where type identifies the image's type (compare source).
You can see that imagick returns the value from some MagickTypeOptions array which is defined here. This array contains an -Alpha and -Matte version for every image type if it's color palette contains alpha.
Theoretically you could save an image with such palette without using it, but every decent programm should swith to the non-alpha version in this case. But false positives are possible but should be rare.
Also I don't check for the -Matte image types because in the array is defined in a way that for every image type constant there are two entries with different names (-Alpha and -Matte), but as -Alpha comes first this name will be returned for that image type.

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