I was trying to perform a crop on a image using imagemagick. It did not give the results I expected.
I decided to set the crop value to 0 to try and find the error.
With a crop value of 0 the image was still being cropped.
Here is the code:
$img = new Imagick();
$img->readImage("{german-grammar.pdf}[17]");
$img->trimImage(10);
$width = $img->getImageWidth();
$height= $img->getImageHeight();
$img->setImagePage($width,$height, 0, 0); //Solution
$img->cropImage($width, $height,0,0); //Original Problem lime
$img->setImagePage(0,0,0,0);
$img->writeImage($ImagesPath.$ImageName);
The input is a PDF file.
I would appreciate if anyone could tell me what I am doing wrong.
Surely a crop value of 0 should not crop at all.
Thanks!
Cymro
I think you need to repage your image immediately after the trimImage() and before the cropImage(). It is generally a good idea to repage an image after any changes to its geometry (such as trimming and resizing) if you want the image to forget that it was once part of a larger image and go forth in the world happy and content with its own new shape and size.
Related
I have pieced together a PHP class to perform various image related functions using GD functions of PHP.
It works great for all image types. Rotate, flip, resize, crop and to a lesser extent, watermark.
All but the latter work perfectly. For example after a few changes, rotated PNG images retained their transparency whereas before they were losing that and the background turning black. Common problem, it appears. But all working now.
Where I'm still getting stuck is watermarking a PNG image with another PNG image. It appears to work fine with JPG and other images. This is the code (simplified):
public function writeWatermarkSimple()
{
$watermarkFile = 'watermark.png';
$watermarkImage = imagecreatefrompng($watermarkFile);
imagealphablending($watermarkImage, false);
imagesavealpha($watermarkImage, true);
$imageFile = 'image.png';
$baseImage = imagecreatefrompng($imageFile);
imagealphablending($baseImage, false);
imagesavealpha($baseImage, true);
$marginH = imagesx($baseImage) - imagesx($watermarkImage);
$marginV = imagesy($baseImage) - imagesy($watermarkImage);
$cut = imagecreatetruecolor(imagesx($watermarkImage), imagesy($watermarkImage));
imagecopy($cut, $baseImage, 0, 0, $marginH, $marginV, imagesx($watermarkImage), imagesy($watermarkImage));
imagecopy($cut, $watermarkImage, 0, 0, 0, 0, imagesx($watermarkImage), imagesy($watermarkImage));
imagecopymerge($baseImage, $cut, $marginH, $marginV, 0, 0, imagesx($watermarkImage), imagesy($watermarkImage), 80);
if (!imagepng($baseImage, 'watermarked_image.png'))
{
return false;
}
return true;
}
This has been pieced together with various guides and advice people have given based on a similar issue. Again, working perfectly with JPG images and PNG watermarks, but not PNG & PNG.
Some example images:
http://i.imgur.com/hHRWinj.png - This is the watermark I'm using.
http://i.imgur.com/6sy8Ncs.png - This is the image I'm applying the watermark to.
http://i.imgur.com/ghovYLm.png - This is the end result.
The bit I find interesting is that any part of the watermark that is overlaid on a non-transparent portion of the image is working fine. Just the rest of it has the black background.
This leads me to believe I'm close, and I hope that the expertise of you fine people may lead me to the solution.
Thanks ever so for reading.
So, I'm not giving up on finding the correct answer to do this using GD. However, I was overjoyed to find that what needed up to 30 lines of code with GD can be achieved using much less with ImageMagick:
$image = new Imagick();
$image->readimage($this->_image);
$watermark = new Imagick();
$watermark->readimage($this->_watermark->_getImage());
$watermark->evaluateImage(Imagick::EVALUATE_DIVIDE, 2, Imagick::CHANNEL_ALPHA);
$image->compositeImage($watermark, imagick::COMPOSITE_OVER, $marginH, $marginV);
So this is before (with GD):
http://i.imgur.com/AlS0TcO.png
And after (with ImageMagick and the code above):
http://i.imgur.com/zBxlC3R.png
If anyone has an answer that is purely GD then I'd be immensely grateful.
Ran into some similar issues recently and while this may not exactly solve your problem, these were some useful discoveries that I made.
In my case, I have an original .jpg image and a watermark .png image. The watermark image has a fully transparent background. I wanted to specify the opacity in my script and have it change the watermark opacity before placing it on top of the origina image. Most posts out there regarding PHP watermarking assume that the original watermark .png file already has the solid watermark portion set to the correct opacity rather than changing it via the script.
gd didn't like a 24 bit .png and caused some goofy issues. Switching to 8 bit resolved that with gd. On the other hand, imagick works very well with a 24 bit .png and the final result seems to be better.
For me, using gd worked just fine if I was opening the original watermark .png and using imagecopymerge() to set the watermark transparency. If however I tried to scale the original watermark .png (which has transparent background) first, then I would get similar results as you with black or white background portion of where watermark image is. See How do I resize pngs with transparency in PHP? for a partial solution by filling the new wm image with transparent rectangle first. For me this still produced an opaque white background on the final result no matter what I tried.
I switched to imagick and was using setImageOpacity() to change the transparency of my watermark .png before applying it on top of my original image and I was still getting the same effect with a black background. Finally read in the PHP doc for setImageOpacity() that if the original .png has any transparent pixels and you try to lower the opacity, those pixels become opaque (black) with the new transparency applied. Instead, need to use the evaluateImage() function. This will instead evaluate each pixel's alpha channel only and divide by the specifid number.
I assume the black / white background issue with gd is likely due to similar ways that it treats alpha channels when scaling / combining as compared to imagick and if you want to do it all in gd you just need to find some similar way to evaluate and manipulate the alpha channel per-pixel because the "easy" ways seem to take an already transparent background and make it opaque.
So, the solution:
Assuming you want to apply your watermark at an opacity of 45% and you're using imagick, then instead of this:
$watermark->setImageOpacity(.45);
do this
$watermark->evaluateImage(Imagick::EVALUATE_DIVIDE, (1/.45), Imagick::CHANNEL_ALPHA);
You need to divide 1 by your opacity to get the demoninator by which the function will divide the alpha channel value for each pixel. In this case, 1/.45 = 2.2222, so then the function will divide the alpha channel of each pixel by 2.2222. This means a solid pixel (alpha of 1) would result in 1/2.2222 or .45 alpha or transparency when finished. Any pixels that were already transparent (alpha 0) would stay transparent because 0 divided by anything is always what? Zero!
After you change the watermark transparency then you can use compositeImage() to merge the watermark onto the original image.
I'm trying to get an image and crop it then resize it to a thumbnail using PHPThumb. I want to crop the left side, right side, top and bottom in similar percentages. For example, crop 30% from left and 30% from right side; crop 40% from top bottomwards and 40% from bottom upwards How can I go about it. All I see in the manual is passing the SX value which I suppose only crops it mathematically from the bottom left(where x=0). I need to be able to crop from both sides towards the centre of the image. I hope you get what I mean.
I am using PHPThumb and not something custom since it has good JPEG compression when resizing, therefore the images have the clarity of the originals.
IMPORTANT EDIT: I have been notified that such a feature is not available in PHPThumb, anybody know of any such thumbnaik generator with the above cropping functions?
You could use Imagemagick -shave ( http://www.imagemagick.org/script/command-line-options.php#shave )but would need to calculate the pixels from the percentages first.
Untested code:
$size = getimagesize($input);
$horizontal = round( ($size[0]x0.3), 0);
$vertical = round( $size[1]x0.4), 0);
$cmd = "$input -shave {$horizontal}x{$vertical}";
exec("convert $cmd output.jpg");
I am trying to accomplish this task for 2 days, read various stuffs online but still can't find out what is happen, also read all here at SO about similar problems but nothing.
I have image 400x400 and want to generate 120x120 using php gd. using this code:
$image_p = imagecreatetruecolor(120,120);
$image = imagecreatefromstring($X_IMAGE);
imagecopyresampled($image_p, $image, 0, 0, 0, 0, 120, 120, 400, 400);
// RETURN
header('Content-Type: image/jpeg');
imagejpeg($image_p, null, 70);
//destroy...
$X_IMAGE is 400x400 JPG that is stored as string.
All images are generated in 120x120 but most of them have some BLACK rectangle at bottom at some pictures it is larger on some it is smaller but 50% of images are with that square. So all are VISIBLE, just some part of image is covered with that black color. What would be solution for my problem? All source images are JPG and also those 120x120 that I need are JPG as you can see...
The problem is that your original image is not a square! You pass 400x400 to imagecopyresampled, but the height of the original image maybe is not 400px!
In the image you posted, for example, you have a not-squared original image. When you tell PHP to resample a square on anther image resource, you will resample the image plus a non-existent rectangle at the bottom.
The solution depends on what you want to output.
Do you want a scaled image that keeps ratio? For example, from 400x300 to 120x90.
Or a scaled image that not keeps ratio? For example, from 400x300 to a distorted 120x120?
Or a cropped thumbnail? 400x300 to a 120x120 with left and right parts trimmed out a little?
Do you want to replace the black rectangle with a white one, so fill the resampled image in that way?
I use PHP and Imagick to change the color of a transparent PNG. The image in the PNG is a simple shape with a transparent background.
I use the colorizeImage function to change the color.
$img = new Imagick("shape.png");
$img->colorizeImage("#99ccff",0.0);
The problem is that Imagick show a dark version of my HEX code (#99ccff)?
Is there a way to get the exact color (#99ccff)?
(my PNG is PNG 32 - and the shape is black)
I thought I would answer this question despite that it is old. This is for anyone else having this problem.
I solved this for a project I am working on by simply using "Clut" instead, like so:
$img = new Imagick("shape.png");
$clut = new Imagick();
$clut->newImage(1, 1, new ImagickPixel('#99ccff'));
$img->clutImage($clut);
$clut->destroy();
Hope it helps anyone else having this issue.
$img = new Imagick("shape.png");
$img->colorizeImage("#99ccff",0.0);
That second parameter is opacity. If you set it to 1.0, it will match #99ccff 100%. You can set it to 0.5 to meet 50% over the original layer, etc:
$img = new Imagick("shape.png");
$img->colorizeImage("#99ccff", 1.0);
You must provide opacity, and opacity value MUST be integer 1,
$img->colorizeImage('#99ccff', 1);
or it does not work, i have tested a bit and i think to work with transparency you need to provide alpha channel.
HEllo,
I am trying to rotate a circular image around the center and then cut off the sides. I see the imagerotate function, but it does not seem to rotate about centre.
Anyone have any suggestions?
Thank you.
Update: Since it is a circle, I want to cut off the edges and keep my circle in the same dimensions.
The documentation says that it does rotate around the center.
Unfortunately it also says that it will scale the image so that it still fits. That means that whatever you do this function will change the size of your internal circular image.
You could (relatively easily) calculate how much scaling down will happen and then prescale the image up appropriately beforehand.
If you have the PHP "ImageMagick" functions available you can use those instead - they apparently don't scale the image.
I faced successfully that problem with the following code
$width_before = imagesx($img1);
$height_before = imagesy($img1);
$img1 = imagerotate($img1, $angle, $mycolor);
//but imagerotate scales, so we clip to the original size
$img2 = #imagecreatetruecolor($width_before, $height_before);
$new_width = imagesx($img1); // whese dimensions are
$new_height = imagesy($img1);// the scaled ones (by imagerotate)
imagecopyresampled(
$img2, $img1,
0, 0,
($new_width-$width_before)/2,
($new_height-$height_before)/2,
$width_before,
$height_before,
$width_before,
$height_before
);
$img1 = $img2;
// now img1 is center rotated and maintains original size
Hope it helps.
Bye
According to the PHP manual imagerotate() page:
The center of rotation is the center
of the image, and the rotated image is
scaled down so that the whole rotated
image fits in the destination image -
the edges are not clipped.
Perhaps the visible center of the image is not the actual center?