English
English
First, use PHP’s imagecreatefrom*() functions (such as imagecreatefromjpeg(), imagecreatefrompng(), etc.) to load the original image, or you can create a blank image resource. The imagewbmp function requires a valid image resource as its parameter.
The basic usage of the imagewbmp function is to output the image resource as a WBMP format image. This process does not require any additional image libraries; imagewbmp itself can handle common image resources such as PNG or JPEG.
imagewbmp can output the image directly to the browser or save it to a specified file. By default, imagewbmp outputs to the browser. If you want to save the image on the server, you can specify the file path as the second parameter.
<?php
// Step 1: Load the image file
<p>$image = imagecreatefromjpeg('example.jpg'); // Create an image resource from a JPEG file</p>
<p>// Step 2: Specify the output file path for the WBMP image</p>
<p>$outputFile = 'output_image.wbmp';</p>
<p>// Step 3: Generate and save the WBMP format image</p>
<p>imagewbmp($image, $outputFile);</p>
<p>// Free up resources</p>
<p>imagedestroy($image);</p>
<p>echo "The image has been successfully saved in WBMP format!";<br>
?><br>
imagecreatefromjpeg: Creates an image resource from a JPEG file.
imagewbmp: Outputs the image resource as a WBMP format image. The second parameter is the file save path, which is optional. If omitted, the image is output directly to the browser.
imagedestroy: Destroys the image resource and frees memory.
Finally, the program saves the image as the output_image.wbmp file.
The generated WBMP image can be viewed directly in a browser or downloaded and viewed on devices that support the WBMP format. You can try viewing this image on some older phones or emulators, as the WBMP format was originally designed for early mobile devices.
Color Limitation: WBMP format only supports black and white images. Any input image will be automatically converted to black and white mode, with all colors mapped to either black or white. Therefore, color information in the input image will be lost.
File Size: WBMP images are generally small in size, making them suitable for scenarios requiring the transfer of small files, especially when network bandwidth is limited.
Image Quality: Due to its simplicity, WBMP format is usually not suitable for scenarios requiring high-quality images. It is more appropriate for displaying simple icons or low-resolution images.
