What should I do if the image converted to php does not display?

In web development, we often need to display pictures dynamically generated by PHP on the page. However, during the development process, sometimes we find that the generated images cannot be displayed on the page. How to solve this problem? This article will discuss this issue.

First of all, let us take a look at why the images generated by PHP are not displayed. Generally speaking, this is mainly caused by the following reasons:

1. File path error: If the path of the image is incorrect, the image cannot be displayed correctly on the page.
2. Image format error: Incorrect image format will also result in the inability to display the image correctly on the page. Generally speaking, common image formats include JPEG, PNG, GIF, etc. We need to ensure that the generated image format is correct.
3. PHP GD library problem: PHP's function of generating images is generally implemented by relying on the GD library. If the GD library is not installed or configured correctly, the generated images will not be displayed correctly.

In response to the above problems, we can adopt the following solutions:

1. Check whether the file path is correct: We can check by outputting the image path on the web page or using developer tools Is the path correct? If the path is wrong, it needs to be corrected in time.
2. Make sure the image format is correct: We can check whether the image format is correct by checking whether the image can be displayed correctly in the browser. If the format is wrong, you need to regenerate the image in the correct format.
3. Check whether the GD library is correctly installed: We can check whether the GD library is correctly installed through the PHP system function phpinfo(). If the GD library is not installed, you need to install the GD library first and configure it into the PHP environment.

In addition to the above solutions, there are some common problems and solutions as follows:

1. Insufficient memory: When generating large pictures, insufficient memory may occur. We can solve this problem by adjusting PHP's memory limit.
2. Image caching: The browser may cache images, causing the images on the page not to be updated. We can solve this problem by adding a timestamp parameter to the URL requesting the image or setting a cache control header.

Finally, to summarize, the main reasons why PHP-generated images are not displayed are file path errors, image format errors and GD library issues. We can take corresponding solutions to these problems. In addition, you also need to pay attention to issues such as insufficient memory and image caching. I hope this article can be helpful to everyone.

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