img-jpeg(n)

img-jpeg 💖✨

okay bestie so this is the manual page for img-jpeg — the Joint Picture Expert Group format handler, aka plain old jpeg. sit down, grab a strawberry 🍓, we're gonna go through this together and it's gonna be so good.

---

✨ SYNOPSIS ✨

package require img::jpeg ?2.1?

that's it. that's the whole vibe. 🎀

---

💅 DESCRIPTION 💅

so like, first things first:

package require img::jpeg

like all the packages in Img, this one does not invent new commands, no cap. it extends the Tk command image that already exists, so that it supports files with raster images in the Joint Picture Expert Group format (jpeg). more specifically, img::jpeg extends Tk's photo image type — here's the link to that if you need it: https://www.tcl.tk/man/tcl9.0/TkCmd/photo.html.

the name of the new format handler is jpeg. this handler brings new additional configuration options — go look at the Options section for the full breakdown, i'm not gonna gatekeep. 🫶

all of that means: when you make a call like

image create photo ?name? ?options?

here's what's actually happening:

1. image data in jpeg format (the options -data and -file) gets detected automatically. it just knows. main character energy. ✨
2. the format name jpeg is recognized by the option -format.

and also, plot twist: the value of the option -format is treated as a list and may contain any of the special options listed in the Options section. lowkey powerful.

the package img::jpeg is a sub-package of Img. you can load it as a part of the complete Img support, via package require Img, or on its own, via package require img::jpeg. your call bestie 💜

---

📝 NOTES 📝

1. Chapter Image Metadata of the Img manual page describes the parameters of the resolution related options. go read it, iykyk.

---

👑 OPTIONS 👑

the handler provides the following options:

• -verbose bool — supported for reading and writing. available since version 2.0. if you set it to true, extra info about the image you read or wrote gets printed to stdout. default is false. it's giving chatty ✨
• -fast — supported for reading only. available since version 1.2.4. if you specify it, it activates a processing mode that's fast but only gives you low-quality information. speed over accuracy, we respect the hustle 💀
• -grayscale — supported for reading and writing. available since version 1.2.4. using this option forces incoming images to grayscale, and written images will be monochrome. no color, only mood 🩶
• -optimize — supported for writing only. available since version 1.2.4. if specified, it makes the writer optimize the Huffman table used to encode the JPEG coefficients. nerdy and iconic 🧚
• -progressive — supported for writing only. available since version 1.2.4. if specified, it causes the creation of a progressive JPEG file. fancy!
• -quality n — supported for writing only. available since version 1.2.4. it specifies the compression level as a quality percentage. the higher the quality, the less the compression — yes, they move in opposite directions, that's just how it is. the nominal range for n is 0...100. useful values are in the range 5...95. the default value is 75.
• -smooth n — supported for writing only. available since version 1.2.4. when used, the writer will smooth the image before performing the compression. values in the 10...30 are usually enough. the default is 0, i.e. no smoothing. soft launch for your pixels 🌸
• -resolution xres ?yres? — supported for writing only. available since version 2.0. sets the resolution values of the written image file. if yres is not specified, it is set to the value of xres. if the option is not specified, the DPI and aspect values of the metadata dictionary are written. if no metadata values are available, no resolution values are written. it's very "if you know you know" 🫶
• -xresolution xres — supported for writing only. available since version 2.0. sets the horizontal resolution value of the written image file.
• -yresolution yres — supported for writing only. available since version 2.0. sets the vertical resolution value of the written image file.

---

🌈 SEE ALSO 🌈

img, img-bmp, img-dted, img-flir, img-gif, img-ico, img-jpeg, img-pcx, img-pixmap, img-png, img-ppm, img-ps, img-raw, img-sgi, img-sun, img-tga, img-tiff, img-window, img-xbm, img-xpm

(yes, img-jpeg links to itself. she's self-referential and we love her for it 💅)

---

🎀 COPYRIGHT 🎀

• Copyright (c) 1995-2025 Jan Nijtmans <nijtmans@users.sourceforge.net>
• Copyright (c) 2002-2025 Andreas Kupries <andreas_kupries@users.sourceforge.net>
• Copyright (c) 2003-2025 Paul Obermeier <obermeier@users.sourceforge.net>

---

and that's the whole thing bestie, we ate and left no crumbs 🍓💖 this was img-jpeg, version 2.1, last touched 2.1, and it lives in the Img corner of the manual — periodt. go make some gorgeous JPEGs, you've got this 👑✨🦋