Chrome Extensions Download All Images
Dibe Naro
The first thing I noticed when making the switch is that I could no longer right-click an image and directly Save Image to "Downloads". When designing and developing webpages I use this feature quite frequently, grabbing images from different sites for mockup purposes. Chrome has a similar sounding item in its right click contextual menu called Save Image As..., but it behaves quite differently.
I am trying to make my first Chrome extension. It creates a popup window that needs to have certain images on it, which are stored in the extension folder. I have this code for putting an image in the popup window:
Good choice for both images and animated images due to high performance and royalty free image format. It offers much better compression than PNG or JPEG with support for higher color depths, animated frames, transparency, etc. Note that when using AVIF, you should include fallbacks to formats with better browser support (i.e. using the element).
Support: Chrome, Edge, Firefox (still images only: animated images not implemented), Opera, Safari.
Good choice for lossy compression of still images (currently the most popular). Prefer PNG when more precise reproduction of the image is required, or WebP/AVIF if both better reproduction and higher compression are required.
Support: Chrome, Edge, Firefox, IE, Opera, Safari.
PNG is preferred over JPEG for more precise reproduction of source images, or when transparency is needed. WebP/AVIF provide even better compression and reproduction, but browser support is more limited.
Support: Chrome, Edge, Firefox, IE, Opera, Safari.
APNG is a file format first introduced by Mozilla which extends the PNG standard to add support for animated images. Conceptually similar to the animated GIF format which has been in use for decades, APNG is more capable in that it supports a variety of color depths, whereas animated GIF supports only 8-bit indexed color.
Note: AVIF has potential to become the "next big thing" for sharing images in web content. It offers state-of-the-art features and performance, without the encumbrance of complicated licensing and patent royalties that have hampered comparable alternatives.
AVIF is supported in Chrome, Edge, Opera, Safari and Firefox (Firefox supports still images but not animations). As support is not yet comprehensive (and has little historical depth) you should provide a fallback in WebP, JPEG or PNG format using the element (or some other approach).
Each pixel in a GIF is represented by a single 8-bit value serving as an index into a palette of 24-bit colors (8 bits each of red, green, and blue). The length of a color table is always a power of 2 (that is, each palette has 2, 4, 8, 16, 32, 64, or 256 entries). To simulate more than 255 or 256 colors, dithering is generally used. It is technically possible to tile multiple image blocks, each with its own color palette, to create truecolor images, but in practice this is rarely done.
GIF is a good choice for simple images and animations, although converting full color images to GIF can result in unsatisfactory dithering. Typically, modern content should use PNG for lossless and indexed still images, and should consider using APNG for lossless animation sequences.
The JPEG (typically pronounced "jay-peg") image format is currently the most widely used lossy compression format for still images. It's particularly useful for photographs; applying lossy compression to content requiring sharpness, like diagrams or charts, can produce unsatisfactory results.
JPEG is actually a data format for compressed photos, rather than a file type. The JFIF (JPEG File Interchange Format) specification describes the format of the files we think of as "JPEG" images.
SVG is an XML-based vector graphics format that specifies the contents of an image as a set of drawing commands that create shapes, lines, apply colors, filters, and so forth. SVG files are ideal for diagrams, icons, and other images which can be accurately drawn at any size. As such, SVG is popular for user interface elements in modern Web design.
SVG is an ideal choice for images which can be represented using a series of drawing commands, especially if the size at which the image will be rendered is unknown or may vary, since SVG will smoothly scale to the desired size. It's not generally useful for strictly bitmap or photographic images, although it is possible to include bitmap images within an SVG.
TIFF is a raster graphics file format which was created to store scanned photos, although it can be any kind of image. It is a somewhat "heavy" format, in that TIFF files have a tendency to be larger than images in other formats. This is because of the metadata often included, as well as the fact that most TIFF images are either uncompressed or use compression algorithms that still leave fairly large files after compression.
A single TIFF file can contain multiple images; this may be used to represent multi-page documents, for example (such as a multi-page scanned document, or a received fax). However, software reading TIFF files is only required to support the first image.
Long ago, some browsers supported TIFF images in web content; today, however, you need to use special libraries or browser add-ons to do so. As such, TIFF files are not useful within the context of web content, but it's common to provide downloadable TIFF files when distributing photos and other artwork intended for precision editing or printing.
XBM uses a snippet of C code to represent the contents of the image as an array of bytes. Each image consists of 2 to 4 #define directives, providing the width and height of the bitmap (and optionally the hotspot, if the image is designed as a cursor), followed by an array of unsigned char, where each value contains 8 1-bit monochrome pixels.
For smaller images such as icons, use a lossless format to avoid loss of detail in a size-constrained image. While lossless WebP is ideal for this purpose, support is not widespread yet, so PNG is a better choice unless you offer a fallback. If your image contains fewer than 256 colors, GIF is an option, although PNG often compresses even smaller with its indexed compression option (PNG-8).
While the standard HTML element doesn't support compatibility fallbacks for images, the element does. is used as a wrapper for a number of elements, each specifying a version of the image in a different format or under different media conditions, as well as an element which defines where to display the image and the fallback to the default or "most compatible" version.
\n Good choice for both images and animated images due to high performance and royalty free image format.\n It offers much better compression than PNG or JPEG with support for higher color depths, animated frames, transparency, etc.\n Note that when using AVIF, you should include fallbacks to formats with better browser support (i.e. using the\n element).
Support: Chrome, Edge, Firefox (still images only: animated images not implemented), Opera, Safari.\n
\n Good choice for lossy compression of still images (currently the most\n popular). Prefer PNG when more precise reproduction of the image is\n required, or WebP/AVIF if both better reproduction and higher compression are required.
Support: Chrome, Edge, Firefox, IE, Opera, Safari.\n
\n PNG is preferred over JPEG for more precise reproduction of source\n images, or when transparency is needed. WebP/AVIF provide even better compression and reproduction, but browser support is more limited.
Support: Chrome, Edge, Firefox, IE, Opera, Safari.\n
\n APNG is a file format first introduced by Mozilla which extends the PNG standard to add support for animated images.\n Conceptually similar to the animated GIF format which has been in use for decades, APNG is more capable in that it supports a variety of color depths, whereas animated GIF supports only 8-bit indexed color.\n
\n Note: AVIF has potential to become the \"next big thing\" for sharing images in web content.\n It offers state-of-the-art features and performance, without the encumbrance of complicated licensing and patent royalties that have hampered comparable alternatives.\n
\n AVIF is supported in Chrome, Edge, Opera, Safari and Firefox (Firefox supports still images but not animations).\n As support is not yet comprehensive (and has little historical depth) you should provide a fallback in WebP, JPEG or PNG format using the element (or some other approach).\n
\n Each pixel in a GIF is represented by a single 8-bit value serving as an index into a palette of 24-bit colors (8 bits each of red, green, and blue). The length of a color table is always a power of 2 (that is, each palette has 2, 4, 8, 16, 32, 64, or 256 entries).\n To simulate more than 255 or 256 colors, dithering is generally used.\n It is technically possible to tile multiple image blocks, each with its own color palette, to create truecolor images, but in practice this is rarely done.\n
\n GIF is a good choice for simple images and animations, although converting full color images to GIF can result in unsatisfactory dithering.\n Typically, modern content should use PNG for lossless and indexed still images, and should consider using APNG for lossless animation sequences.\n
\n The JPEG (typically pronounced \"jay-peg\") image format is currently the most widely used lossy compression format for still images.\n It's particularly useful for photographs; applying lossy compression to content requiring sharpness, like diagrams or charts, can produce unsatisfactory results.\n
\n JPEG is actually a data format for compressed photos, rather than a file type.\n The JFIF (JPEG File Interchange Format) specification describes the format of the files we think of as \"JPEG\" images.\n
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