Images · Phalcon3中文文檔

# Images [Phalcon\\Image](http://docs.iphalcon.cn/api/Phalcon_Image.html)is the component that allows you to manipulate image files. Multiple operations can be performed on the same image object. > This guide is not intended to be a complete documentation of available methods and their arguments. Please visit the[API](http://docs.iphalcon.cn/api/index.html)for a complete reference. ## Adapters This component makes use of adapters to encapsulate specific image manipulator programs. The following image manipulator programs are supported: | Class | Description | | --- | --- | | [Phalcon\\Image\\Adapter\\Gd](http://docs.iphalcon.cn/api/Phalcon_Image_Adapter_Gd.html) | Requires the[GD PHP extension](http://php.net/manual/en/book.image.php). | | [Phalcon\\Image\\Adapter\\Imagick](http://docs.iphalcon.cn/api/Phalcon_Image_Adapter_Imagick.html) | Requires the[ImageMagick PHP extension](http://php.net/manual/en/book.imagick.php). | ### Implementing your own adapters The[Phalcon\\Image\\AdapterInterface](http://docs.iphalcon.cn/api/Phalcon_Image_AdapterInterface.html)interface must be implemented in order to create your own image adapters or extend the existing ones. ## Saving and rendering images Before we begin with the various features of the image component, it’s worth understanding how to save and render these images. ~~~ <?php $image = new \Phalcon\Image\Adapter\Gd("image.jpg"); // ... // Overwrite the original image $image->save(); ~~~ ~~~ <?php $image = new \Phalcon\Image\Adapter\Gd("image.jpg"); // ... // Save to 'new-image.jpg' $image->save("new-image.jpg"); ~~~ You can also change the format of the image: ~~~ <?php $image = new \Phalcon\Image\Adapter\Gd("image.jpg"); // ... // Save as a PNG file $image->save("image.png"); ~~~ When saving as a JPEG, you can also specify the quality as the second parameter: ~~~ <?php $image = new \Phalcon\Image\Adapter\Gd("image.jpg"); // ... // Save as a JPEG with 80% quality $image->save("image.jpg", 80); ~~~ ## Resizing images There are several modes of resizing: * `\Phalcon\Image::WIDTH` * `\Phalcon\Image::HEIGHT` * `\Phalcon\Image::NONE` * `\Phalcon\Image::TENSILE` * `\Phalcon\Image::AUTO` * `\Phalcon\Image::INVERSE` * `\Phalcon\Image::PRECISE` ### `\Phalcon\Image::WIDTH` The height will automatically be generated to keep the proportions the same; if you specify a height, it will be ignored. ~~~ <?php $image = new \Phalcon\Image\Adapter\Gd("image.jpg"); $image->resize( 300, null, \Phalcon\Image::WIDTH ); $image->save("resized-image.jpg"); ~~~ ### `\Phalcon\Image::HEIGHT` The width will automatically be generated to keep the proportions the same; if you specify a width, it will be ignored. ~~~ <?php $image = new \Phalcon\Image\Adapter\Gd("image.jpg"); $image->resize( null, 300, \Phalcon\Image::HEIGHT ); $image->save("resized-image.jpg"); ~~~ ### `\Phalcon\Image::NONE` The`NONE`constant ignores the original image’s ratio. Neither width and height are required. If a dimension is not specified, the original dimension will be used. If the new proportions differ from the original proportions, the image may be distorted and stretched. ~~~ <?php $image = new \Phalcon\Image\Adapter\Gd("image.jpg"); $image->resize( 400, 200, \Phalcon\Image::NONE ); $image->save("resized-image.jpg"); ~~~ ### `\Phalcon\Image::TENSILE` Similar to the`NONE`constant, the`TENSILE`constant ignores the original image’s ratio. Both width and height are required. If the new proportions differ from the original proportions, the image may be distorted and stretched. ~~~ <?php $image = new \Phalcon\Image\Adapter\Gd("image.jpg"); $image->resize( 400, 200, \Phalcon\Image::NONE ); $image->save("resized-image.jpg"); ~~~ ## Cropping images For example, to get a 100px by 100px square from the centre of the image: ~~~ <?php $image = new \Phalcon\Image\Adapter\Gd("image.jpg"); $width = 100; $height = 100; $offsetX = (($image->getWidth() - $width) / 2); $offsetY = (($image->getHeight() - $height) / 2); $image->crop($width, $height, $offsetX, $offsetY); $image->save("cropped-image.jpg"); ~~~ ## Rotating images ~~~ <?php $image = new \Phalcon\Image\Adapter\Gd("image.jpg"); // Rotate an image by 90 degrees clockwise $image->rotate(90); $image->save("rotated-image.jpg"); ~~~ ## Flipping images You can flip an image horizontally (using the`\Phalcon\Image::HORIZONTAL`constant) and vertically (using the`\Phalcon\Image::VERTICAL`constant): ~~~ <?php $image = new \Phalcon\Image\Adapter\Gd("image.jpg"); // Flip an image horizontally $image->flip( \Phalcon\Image::HORIZONTAL ); $image->save("flipped-image.jpg"); ~~~ ## Sharpening images The`sharpen()`method takes a single parameter - an integer between 0 (no effect) and 100 (very sharp): ~~~ <?php $image = new \Phalcon\Image\Adapter\Gd("image.jpg"); $image->sharpen(50); $image->save("sharpened-image.jpg"); ~~~ ## Adding watermarks to images ~~~ <?php $image = new \Phalcon\Image\Adapter\Gd("image.jpg"); $watermark = new \Phalcon\Image\Adapter\Gd("me.jpg"); // Put the watermark in the top left corner $offsetX = 10; $offsetY = 10; $opacity = 70; $image->watermark( $watermark, $offsetX, $offsetY, $opacity ); $image->save("watermarked-image.jpg"); ~~~ Of course, you can also manipulate the watermarked image before applying it to the main image: ~~~ <?php $image = new \Phalcon\Image\Adapter\Gd("image.jpg"); $watermark = new \Phalcon\Image\Adapter\Gd("me.jpg"); $watermark->resize(100, 100); $watermark->rotate(90); $watermark->sharpen(5); // Put the watermark in the bottom right corner with a 10px margin $offsetX = ($image->getWidth() - $watermark->getWidth() - 10); $offsetY = ($image->getHeight() - $watermark->getHeight() - 10); $opacity = 70; $image->watermark( $watermark, $offsetX, $offsetY, $opacity ); $image->save("watermarked-image.jpg"); ~~~ ## Blurring images The`blur()`method takes a single parameter - an integer between 0 (no effect) and 100 (very blurry): ~~~ <?php $image = new \Phalcon\Image\Adapter\Gd("image.jpg"); $image->blur(50); $image->save("blurred-image.jpg"); ~~~ ## Pixelating images The`pixelate()`method takes a single parameter - the higher the integer, the more pixelated the image becomes: ~~~ <?php $image = new \Phalcon\Image\Adapter\Gd("image.jpg"); $image->pixelate(10); $image->save("pixelated-image.jpg"); ~~~