How to convert image format to jpg in php

Image format to JPG: using PHP

Images are one of the basic elements in our websites and applications. However, sometimes we need to convert pictures to other formats. Among them, converting pictures to JPG format is one of the most common needs. In this article, we will learn how to convert images to JPG format using PHP language.

Why should you convert pictures to JPG format?

The JPG format is a picture format that can achieve a high compression ratio while maintaining close to true colors. Therefore, JPG format images are widely used on the Internet. In fact, most images transferred over the Internet are transferred in JPG format.

When do you need to convert images to JPG format?

There are many situations when we need to convert pictures to JPG format, the following are some of them:

• When we need to upload pictures to the Internet, since JPG format can be compressed The size of the image, thus increasing upload and download speeds.
• When we need to display high-quality pictures on the website, the JPG format can provide the best visual effect.
• When we need to attach a picture to an email, we need to send the picture in JPG format due to the size limit of the email.

How to convert pictures to JPG format using PHP?

Now we know why we need to convert images to JPG format, and under what circumstances we need to do this. Now, let's start learning how to achieve this task using PHP.

Step one: Use PHP function to open the picture

First, we need to use PHP function to open the picture that needs to be converted to JPG format. We can open the image using the following function:

$source_image = imagecreatefromjpeg("path/to/image.jpg");

Here, we have opened the image using the "imagecreatefromjpeg()" function and stored it in a variable named "$source_image". If you need to open other types of images, you need to use different functions, for example:

• imagecreatefrompng() - Open PNG images
• imagecreatefromgif() - Open GIF images

Step 2: Create a new JPG file

Now, we need to create a new JPG file in which to store our converted pictures. We can use the following function to create a new JPG file:

imagejpeg($source_image, "path/to/new_image.jpg");

Here, the "imagejpeg()" function converts the image in the "$source_image" variable to JPG format and stores it in a file named This functionality is implemented in the new file "new_image.jpg". We can replace "path/to/new_image.jpg" with any other file path and name.

Step 3: Release the memory and complete the operation

After we complete the conversion, we can use the following function to release the resources used in the memory and end the operation:

imagedestroy($source_image);

Here, the "imagedestroy()" function simply releases the resource used in memory (here is the image "$source_image" we opened in the first step). Now, we have successfully converted the image to JPG format and saved it.

The following is the complete PHP code:

<?php
// 打开原图片
$source_image = imagecreatefromjpeg("path/to/image.jpg");

// 创建新的JPG文件
imagejpeg($source_image, "path/to/new_image.jpg");

// 释放内存
imagedestroy($source_image);
?>

Conclusion

In this article, we learned how to easily convert images to JPG format using PHP language. This is a very common task and we can accomplish it easily using the functions presented in this article. If you want to know more about PHP and image processing, keep reading our blog.

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