I'm trying to finish up my image uploader that utilizes imagick for the handling of various image types. One thing specifically that I'm trying to get working is the conversion of jpeg files to progressive jpeg. I've tried the following code below, but when I view the images that get output in irfranview, the jpeg are not progressive. Any ideas? This literally must work by Monday.. Please help
foreach ($thumbnailScaleWidths as $thumbnailScaleWidth) {
$thumbnail = new imagick($uploadedFile['tmp_name']);
$thumbnailDimensions = $thumbnail->getImageGeometry();
$thumbnailWidth = $thumbnailDimensions['width'];
$thumbnailHeight = $thumbnailDimensions['height'];
$thumbnailScaleHeight = ($thumbnailScaleWidth / $thumbnailWidth) * $thumbnailHeight;
$thumbnail->thumbnailImage($thumbnailScaleWidth, $thumbnailScaleHeight);
$thumbnail->setImageInterlaceScheme(Imagick::INTERLACE_PLANE);
$thumbnail->writeImages($_SERVER['DOCUMENT_ROOT'] . "/Resources/Media/$userId/$internalName-$thumbnailScaleWidth.$fileType", true);
}
Any ideas as to why this isn't outputting progressive jpegs?
I know this thread is old but here is an answer that might save time to others in the future.
So since you are reading an image from file, you should use the following method instead:
Imagick::setInterlaceScheme
It seems that Imagick::setImageInterlaceScheme will work only when Imagick is used to generate an image by itself...
Related
I've been using a great class to manipulate images for a number of years.
class.upload.php
Currently I need to be able to determine if the image is side wards and rotate it, to vertical position. I understand that I can use
$handle->image_auto_rotate = true;
But for some reason I'm not having much luck. The image I was testing with is JPEG.
What am I missing?
Use: $handle->image_rotate = '90';
I have a site with about 1500 JPEG images, and I want to compress them all. Going through the directories is not a problem, but I cannot seem to find a function that compresses a JPEG that is already on the server (I don't want to upload a new one), and replaces the old one.
Does PHP have a built in function for this? If not, how do I read the JPEG from the folder into the script?
Thanks.
you're not telling if you're using GD, so i assume this.
$img = imagecreatefromjpeg("myimage.jpg"); // load the image-to-be-saved
// 50 is quality; change from 0 (worst quality,smaller file) - 100 (best quality)
imagejpeg($img,"myimage_new.jpg",50);
unlink("myimage.jpg"); // remove the old image
I prefer using the IMagick extension for working with images. GD uses too much memory, especially for larger files. Here's a code snippet by Charles Hall in the PHP manual:
$img = new Imagick();
$img->readImage($src);
$img->setImageCompression(Imagick::COMPRESSION_JPEG);
$img->setImageCompressionQuality(90);
$img->stripImage();
$img->writeImage($dest);
$img->clean();
You will need to use the php gd library for that... Most servers have it installed by default. There are a lot of examples out there if you search for 'resize image php gd'.
For instance have a look at this page http://911-need-code-help.blogspot.nl/2008/10/resize-images-using-phpgd-library.html
The solution provided by vlzvl works well. However, using this solution, you can also overwrite an image by changing the order of the code.
$image = imagecreatefromjpeg("image.jpg");
unlink("image.jpg");
imagejpeg($image,"image.jpg",50);
This allows you to compress a pre-existing image and store it in the same location with the same filename.
I'm trying to finish up my image uploader that utilizes imagick for the handling of various image types. One thing specifically that I'm trying to get working is the conversion of jpeg files to progressive jpeg. I've tried the following code below, but when I view the images that get output in irfranview, the jpeg are not progressive. Any ideas?
foreach ($thumbnailScaleWidths as $thumbnailScaleWidth) {
$thumbnail = new imagick($uploadedFile['tmp_name']);
$thumbnailDimensions = $thumbnail->getImageGeometry();
$thumbnailWidth = $thumbnailDimensions['width'];
$thumbnailHeight = $thumbnailDimensions['height'];
$thumbnailScaleHeight = ($thumbnailScaleWidth / $thumbnailWidth) * $thumbnailHeight;
$thumbnail->thumbnailImage($thumbnailScaleWidth, $thumbnailScaleHeight);
$thumbnail->setImageInterlaceScheme(Imagick::INTERLACE_PLANE);
$thumbnail->writeImages($_SERVER['DOCUMENT_ROOT'] . "/Resources/Media/$userId/$internalName-$thumbnailScaleWidth.$fileType", true);
}
Any ideas as to why this isn't outputting progressive jpegs?
Use setInterlaceScheme instead of setImageInterlaceScheme - the latter doesn't appear to do anything, but the former works just fine for me.
I've heard that the best way to handle uploaded images is to "re-process" them using the GD library and save the processed image. see: PHP image upload security check list
My question is how do this "re-processing" in GD? What this means exactly? I don't know the GD library very well and I'm afraid I will mess it up...
So if anyone who did this before could you give me an example for this?
(I know, another other option is to use ImageMagick. For ImageMagick I found an answer here: Remove EXIF data from JPG using PHP, but I can't use ImgMagick now. By the way.. removing EXIF data means completely recreate the image in this case?)
(I'm using Zend Framework if someone interested.)
If the user uploads a JPEG file, you could do something like this to reprocess it:
$newIm = #imagecreatefromjpeg($_FILES['file']['tmp_name']);
if (!$newIm) {
// gd could not create an image from the source
// most likely, the file was not a valid jpeg image
}
You could then discard the $newIm image using imagedestroy() and use the uploaded file from the user, or save out the image from GD and use that. There could be some issues with saving the GD image as it is not the original image.
Another simple method would be to check the header (first several bytes) of the image file to make sure it is correct; for example all JPEG files begin with 0xff 0xd8.
See also imagecreatefromstring(), and you can also use getimagesize() to run similar checks on the uploaded image.
function isvalidjpeg($file)
{
$finfo = finfo_open(FILEINFO_MIME_TYPE);
return is_resource($finfo) &&
(finfo_file($finfo, $file) === 'image/jpeg') &&
finfo_close($finfo);
}
if(isvalidjpeg($_FILES['file']['tmp_name'])) {
$newIm = #imagecreatefromjpeg($_FILES['file']['tmp_name']); .....
I have a site where users can upload images. I process these images directly and resize them into 5 additional formats using the CodeIgniter Image Manipulation class. I do this quite efficiently as follow:
I always resize from the previous format, instead of from the original
I resize using an image quality of 90% which about halves the file size of jpegs
The above way of doing things I implemented after advise I got from another question I asked. My test case is a 1.6MB JPEG in RGB mode with a high resolution of 3872 x 2592. For that image, which is kind of borderline case, the resize process in total takes about 2 secs, which is acceptable to me.
Now, only one challenge remains. I want the original file to be compressed using that 90% quality but without resizing it. The idea being that that file too will take half the file size. I figured I could simply resize it to its' current dimensions, but that doesn't seem to do anything to the file or its size. Here's my code, somewhat simplified:
$sourceimage = "test.jpg";
$resize_settings['image_library'] = 'gd2';
$resize_settings['source_image'] = $sourceimage;
$resize_settings['maintain_ratio'] = false;
$resize_settings['quality'] = '90%';
$this->load->library('image_lib', $resize_settings);
$resize_settings['width'] = $imagefile['width'];
$resize_settings['height'] = $imagefile['height'];
$resize_settings['new_image'] = $filename;
$this->image_lib->initialize($resize_settings);
$this->image_lib->resize();
The above code works fine for all formats except the original. I tried debugging into the CI class to see why nothing happens and I noticed that the script detects that the dimensions did not change. Next, it simply makes a copy of that file without processing it at all. I commented that piece of code to force it to resize but now still nothing happens.
Does anybody know how to compress an image (any image, not just jpegs) to 90% using the CI class without changing the dimensions?
I guess you could do something like this:
$original_size = getimagesize('/path/to/original.jpg');
And then set the following options like this:
$resize_settings['width'] = $original_size[0];
$resize_settings['height'] = $original_size[1];
Ok, so that doesn't work due to CI trying to be smart, the way I see it you've three possible options:
Rotate the Image by 360ยบ
Watermark the Image (with a 1x1 Transparent Image)
Do It Yourself
The DIY approach is really simple, I know you don't want to use "custom" functions but take a look:
ImageJPEG(ImageCreateFromString(file_get_contents('/path/to/original.jpg')), '/where/to/save/optimized.jpg', 90);
As you can see, it's even more simpler than using CI.
PS: The snippet above can open any type of image (GIF, PNG and JPEG) and it always saves the image as JPEG with 90% of quality, I believe this is what you're trying to archive.