What is "Save all Images" extension and how does it work?

This extension adds an action button to your browser. When you click on the button, a filtering window will open. At the top of the window, you will see the "statistic" panel. This panel provides information about the detected images. It has three sub-sections: "Total," "Processed," and "Save."

The "Total" label displays the total number of detected images on the current page. The "Processed" label shows the number of images whose size and type have been resolved by sending a HEAD request to the server. Once a reply is received, the "Processed" count will be incremented. The "Save" label shows the total number of images that will be saved based on the current filter settings.

How many images will be saved if I press the "OK" button?

The "statistic" section displays the number of images that the extension saves. Keep in mind that the filters are divided into different groups, and an "AND" operation is applied to all of them. This means that an image must meet all the filtering rules to be added to the download queue. If you only want to download images based on one criterion, uncheck the other filters. You can switch to the gallery tab to see the results based on the current filtering criteria.

How does the extension determine the size of an image, and what happens if it cannot get resolved?

There are two different cases to consider. The image might use the HTTP or HTTPS schemes, or it might use the Data URI scheme. For URLs using the HTTP/HTTPS schemes, the extension sends a "HEAD" request to the server and analyzes the response headers to obtain the image type and size. For URLs using the Data URI scheme, both the size and type are embedded in the scheme, so there is no need to send a request to the server.

If a server does not support "HEAD" requests, the extension will return null, and the image selection rule will depend on your settings. You can choose to accept or reject images with unknown sizes. To find the number of images with unknown sizes, you can enable the size filter, press "save" and "ignore" for unknown sizes once, and compare the resulting numbers.

What's new in this version?

Please check the Logs section.

How does the regular expression filter work?

The regular expression filter allows you to use a custom regular expression to filter images based on their URL. If the filter is enabled, it will compare the src URL of each image to the regular expression you have entered. The image will be included or excluded based on the result if there is a match. If you are not familiar with regular expressions and would like to learn more, you can refer to developer.mozilla.org/.../Regular_Expressions. This resource provides a detailed guide on how to write regular expression rules.

What is the purpose of the "Only save images from the same domain" option?

Websites often use resources from CDNs and other networks. For example, a hosting website might have a discussion section with images loaded in frames. By default, the extension detects all the images currently loaded on the page, regardless of their origins. However, you can use the "Only save images from the same domain" option to limit image detection to the current domain and eliminate any images loaded from other resources. This filtering help significantly reduces the number of downloaded images.

If a website has nested iframes (iframes inside iframes), will this extension detect images in those iframes as well?

Yes, the extension can detect all images loaded on the page, regardless of whether they are inside a nested iframe. There is no limit on the detection method when it comes to nested iframes. The extension will inspect all iframes, including nested ones, and report on any images that are loaded within them. If you want to ignore third-party images, you can use the "Only save images from the same domain" filter.

Why is the displayed "processed" number sometimes different from the "total" number of detected images?

There are situations in which some servers do not respond to the "HEAD" request used to determine the image type and size. In these cases, the extension attempts to detect these values based on the image URL, but this is not always an effective method. As a result, the "processed" number may differ from the "total" number of detected images. Also, the website might have used broken ones or images with an invalid response.

Why do I get the error "Cannot collect images on this tab" and how can I fix it?

You may receive this error if you try to collect images from web stores such as mozilla.addon.org on Firefox or chrome.google.com on Google Chrome. This is due to security measures that prevent extensions from injecting scripts into protected pages. Unfortunately, there is no workaround for this issue. Keep in mind that you can still use a different browser, such as Google Chrome, to collect images on addon.mozilla.org.

You may also receive this error if you try to collect images from another extension page (extension://*). For more information, please visit github.com/.../save-images/issues/2.

Can I download image links that are stored in a text file using this extension?

You can download image links stored in a text file using this extension. To do so, you will need to allow the extension to access local files (file://...) from the extension manager of your browser. Then, you can drop the file into a browser tab and click on the extension's icon. Set the deep-level value to 1 or 2, depending on whether the links are actual images or they are links to pages that contain the images.

How can I cancel an image-grabbing job?

When the extension inspects a tab, it injects a small script to detect all the images. This process may take some time, depending on the total number of links on the page and its subframes. The extension fetches all the images and then analyzes each one, which adds additional time. To cancel the entire process, close the image-grabbing panel. The download will terminate if the panel is closed during the download stage.

What is the meaning of the formatting in the "Save in" section?

This is the template for generating the filename. The default format is [title] - [date] [time]. To have a fixed name, replace the default template with a static name like "images.zip". To restore the default, clear the formatting box.

What is the meaning of the timeout box in the "Save in" section?

This box defines the default timeout for the extension. This is the time that the extension will wait before interrupting a downloading job. If a server does not respond within this period, the image is considered to be broken.

Why do I sometimes get fewer images in the final ZIP archive than the number shown in the panel?

There are a couple of reasons why you might end up with fewer images in the final ZIP archive. One possibility is that the extension's timeout feature interrupts the downloading job if the server is not responding within the specified period. You can adjust the timeout value in the "Save in" section of the panel UI. Additionally, some images might be broken and therefore are not included in the final archive. The extension provides a text file indicating broken links.

How does the deep search level 2 differ from the deep search level 3?

In the deep search level 2, only IMG tags in destination HTML pages (all web pages except the root one) are considered, while in level 3, the extension evaluated IMG and A tags. Keep in mind that searching at level 3 is a slow process, as the extension needs to evaluate thousands of links. If you plan to use these two levels, make sure to define custom regular expression filters for the domains of interest.

What is the purpose of the customs rules section on the options page and how do I use it?

The custom rules section allows you to define a JSON object to pre-validate all URLs based on the first matching key in the JSON object. The extension uses the keys to match the top-level URL (page URL) and the values to pre-validate each link that will be considered as a potential image link. This validation occurs before the internal validation and can significantly improve the search speed. If you frequently use a particular website, it is recommended to write a JSON matching condition for it to reduce the time the extension needs to validate all the links. For example, consider the task of catching a large screenshot of a page on the WebExtension.ORG host. The key in this case would be a regular expression that only matches WebExtension.ORG web hosting, such as add0n.com. The value would be a regular expression that only matches the large screenshot image, such as -big.png. So the entire JSON object looks like this:

{
  "add0n\\.com": "-big\\.png"
}

Note that you can have multiple values by making an array. Let's catch 48X48 pixel image as well:

{
  "add0n\\.com": ["-big\\.png", "48\\.png"]
}

For this hosting, the images are available in the actual HTML document, so there is no need to parse destination HTML pages. We can set the deep search level to one and the output will be only two images. Note that when a filter matches the top URL, the "Statistics" section will display the total number of regular expressions limiting your search results.

Can I use this extension to extract image files from linked pages on a website that only displays thumbnails on the current page?

Yes, the extension has a "Deep Search" feature on the interface that allows you to do this. On "Deep Search" level "2", the extension will parse any HTML links on the current page and try to extract all image elements from the destination document. On level "3", the extension will evaluate any links on these pages and try to find image links on them too. Keep in mind that level "3" is slow due to the many links that need to be evaluated. Use this level only when necessary.

Sometimes the extension detects images correctly, but when I enable the "Dimensions" filter, it excludes some of them from appearing in the gallery view. How can I fix this?

On the interface, there is an option to force calculate the width and height of each image. When the page has a linked image, the width and height are unknown until the image is loaded on the page. This extension can fetch metadata from the server (the first few bytes of the image) and use an internal module to find the dimensions of the most popular image types. This requires an additional server-side request. Only enable this option if you need to filter images by their dimensions.

How can I ensure that this extension uses the filter matching rules (File Size, Image Types, and Dimensions)?

There are two types of images on each page: image elements, where the extension knows the width and height of each image, and linked images, where everything is unknown. To ensure that the extension uses the filters accurately, you must check both the "Find width and height of all images" and "Confirm mime-types and guess filenames from server" options. Keep in mind that each request adds an extra server-side request, so only enable these options if you need to use the provided filtering rules. Otherwise, you will be sending unnecessary requests to the server.