Imagick::getImageBlob

(PECL imagick 2, PECL imagick 3)

Imagick::getImageBlobReturns the image sequence as a blob

Description

public Imagick::getImageBlob(): string

Implements direct to memory image formats. It returns the image sequence as a string. The format of the image determines the format of the returned blob (GIF, JPEG, PNG, etc.). To return a different image format, use Imagick::setImageFormat().

Parameters

This function has no parameters.

Return Values

Returns a string containing the image.

Errors/Exceptions

Throws ImagickException on error.

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User Contributed Notes 4 notes

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7
Vee W
8 years ago
For who want to show "animated" gif. This getImageBlob() will showing only one frame of image.
Use getImagesBlob() instead.

Example:

<?php
$Imagick
= new \Imagick($real_source_image_path_animated_gif);
header("Content-Type: image/gif");
echo
$Imagick->getImagesBlob();
?>
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2
jim at jimohalloran dot com
3 years ago
Further to Trevor's note above about getImageBlob potentially returning an empty string for large images.

This seems image format dependent. I have a large (12046x8363) image which is returned ok. But if I call setImageFormat('pdf') and then call getImageBlob() again. Example:

<?php
// Image Manipulation here.
$pngData = $imagick->getImageBlob(); // Returns a large PNG.
$imagick->setImageFormat('pdf');
$pdfData = $imagick->getImageBlob(); // Returns empty string immediately
?>
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1
Trevor
12 years ago
It seems that this method can return a zero-length string if faced with large-ish data. No exceptions are thrown.

<?php
$image
= new Imagick();
if (!
$image->newImage(1000,1,'white')) throw new Exception();
if (!
$image->scaleImage(0,200)) throw new Exception();
print
"Image size: {$image->getImageWidth()},{$image->getImageHeight()}\n";
if (!
$image->setImageFormat("jpeg")) throw new Exception();
$a = $image->getImageBlob();
print
"Rendered to ".strlen($a)." bytes\n";
?>

Restrict your output image size, or ensure that the blob you get back isn't empty. (Note that IM seems to be doing the work, it delays for some time. But there's no indication of any error anywhere.)
up
1
anonymous at internet dot domain
6 months ago
Function returns NULL without any error if ImageMagick policy.xml blocks handling the file format, i.e. PDF.
For PDF output edit /etc/ImageMagick-6/policy.xml and remove the line which disables rights for PDF.
If you use other functions, e.g. readImage() for PDF, ImageMagick nags about it and outputs the error message but this function fails silently.
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