I am willing to display a non-ASCII character in Adafruit SSD1306. The corresponding character set is in Unicode. Their library does not show where actually the mapping between ASCII & pixel drawing is done. If it was there, I'd've written code to display the characters that I need.
The hardware library depends on Adafruit GFX library; even this library doesn't explain how the mapping is done.
So, which part of the actually maps an ASCII & pixels on display?
OR Any idea to display Unicodes directly?
OR How'd you get started if pixel by pixel configuration is needed?
I am using Arduino IDE, NodeMCU, Adafruit SSD1306 128x64 I2C monochrome LED display. The text that am trying to display is large and so, am not willing to it in BMP image way.
The mapping between ASCII & pixel drawing is done in the font files.
See:
Adafruit-GFX-Library/Fonts/
Adafruit-GFX-Library/fontconvert/
Adafruit-GFX-Library/gfxfont.h
Adafruit-GFX-Library/glcdfont.c
So maybe you can create your own characters or font to display what you need.
Related
So apparently Overleaf now can render emojis using packages of Noto Color Emojis, where you can use {\NotoEmoji \symbol{"1F343} \symbol{"1F338} } to input an emoji with corresponding unicodes.
My question is how to input complex emojis that are composed of multiple emojis? For example, this one 👩👩👦👦, the unicode is U+1F469 U+200D U+1F469 U+200D U+1F466 U+200D U+1F466.
I've tried combinations like
\symbol{"1F469200d1f469200d...1f466}
\symbol{"1F469 200d 1f469 200d...1f466}
\symbol{"1F469} \symbol{"200d}...\symbol{"1f466}}
But none of them works.
You don't need to concatenate them. Here's the solution that I tried in Overleaf and it worked fine.
{\Large
\NotoEmoji
% family emoji
\symbol{"1F468}\symbol{"200D}\symbol{"1F469}\symbol{"200D}\symbol{"1F467}\symbol{"200D}\symbol{"1F466}
}
Expected Output
👨👩👧👦 Family: Man, Woman, Girl, Boy,
You can use the same trick for Emoji Skin Tone Modifiers in Overleaf where the modifier comes right after the emoji Unicode.
{\Large
\NotoEmoji
% Waving Hand emoji
\symbol{"1F44B}%
% Waving Hand: Light Skin Tone
\symbol{"1F44B}\symbol{"1F3FB}
}
Expected Output
👋
👋🏻
Here's the Overleaf Project page about Displaying Color Emojis in Latex that you can check out.
Updated 2020-11-28 : Adding emoji as an image in Latex
Since you mentioned adding emojis as images, I'm also including my solution for that.
\usepackage{tcolorbox}
% change font size here
\includegraphics[height=12]{family-man-woman-girl-boy.png}
The image can be downloaded from EmojiPedia.
There are some logos for which OCR needs to be run . Logos generally have different fonts. A sample is below. When tesseract was run with all possible psm values RITZ is not getting detected. Also tried converting to black and white using cv2.threshold(grayImage, 120, 255, cv2.THRESH_BINARY) still the R is not getting detected. Can someone tell what technique to be done for these strange fonts. ( I am using python)
It is a problem with tessaract it cant detect complex or handwritten characters. We can use tesseract for simple printed character detection. For complex or handwritten you can try CNN or KNN aalgorithm trained under dataset.(chars74k, A-Z Handwritting)
I am not certain whether this is the right place to ask this, but I do not know of any other sites that would fit better. And the question has something to do with programming, so:
I Am Writing a formatted txt-guide. Please take a look at this excerpt: http://mad-gaksha.homelinux.net/public/width.txt. I need to have full-width characters displayed so that they occupy exactly twice the space as half-width characters. While monospaced fonts seems to work fine with only half-width chars, most fullwidth "fixed-width" fonts I've tried didn't produce the desired result.
In firefox, this works when I set the monospace font (Edit>Preferences>Content>Advanced)to "monospace". But only for a font-size of 14. Same thing with gedit, the fixed-width font MS-Gothic, works only for font sizes 13/14.
As I find this behaviour quite strange and wouldn't want my readers to be troubled by technical details, does anyone have suggestions or give any resources or could explain what's going on here? Why does it seem so hard just to display each glyph with a fixed size?
Thanks in advance for taking your time.
It looks like it's to do with rounding fractional pixels.
A font renderer may adjust horizontal positioning when the width of a glyph isn't a whole number of screen pixels. I believe the Cairo rendering used by gedit and Firefox on Linux doesn't do sub-pixel positioning for fonts so this may be necessary here.
In a true monospace font this doesn't matter because every glyph has the same width so receives the same treatment, but where there is a mixture of full- and half-width characters, the rounding won't be uniform unless the glyphs happen to be a whole number of pixels wide (which happens in your case at font size 14).
Note that on Windows for most small sizes, fonts like MS Gothic will be rendered using custom built-in bitmaps in the font file, instead of rendering the outlines and their metrics. This makes all glyphs necessarily a fixed number of pixels wide. However this does result in the typical old-school ‘jaggy’ rendering style.
If you are producing formatted-text files there is really nothing you can do about this. You can only hope that your target audience has Japanese monospaced fonts that are suitable and can switch to them at a particular font size.
I would agree with Clement's comment that using HTML to get the rendering you want would be more robust, modern and convenient. Using HTML for layout relieves you of having to worry about lining up characters, and allows you to get fonts that are less ugly than all that half-width-monospaced Latin.
I'm trying to use Ghostscript and/or ImageMagick to convert each page of a Postscript document into PNG images. The problem is that both produce images that are way too saturated (I think that's the right terminology).
Here are the commands I'm trying:
gs -dSAFER -dBATCH -dNOPAUSE -sDEVICE=png16m -dGraphicsAlphaBits=4 -sOutputFile=page_%02d.png brochure.ps
convert brochure.ps im_page_%02d.png
This is the input Postscript file (brochure.ps from above)
Here's a couple of the output images I'm getting:
Page 1
Page 6
As you can see (especially on the page with the big green map of New Hampshire), the colors of the output PNGs are too bright/saturated. How can I prevent the colors from being changed so much and get a more accurate conversion?
Preview in OS X 10.6 automatically does a very accurate conversion to PNG when you open a Postscript file in it. This leads me to believe there is just something screwy with the way ghostscript converts ps->png (I'm fairly confident ImageMagick is just a wrapper for ghostscript for this operation). Is there a tool besides ghostscript I should be using instead?
Note: As pipitas points out below, the visible difference of colors varies by OS. It is very obvious in OS X 10.6, but apparently not very noticeable in Windows XP.
You are right in assuming ImageMagick just being a wrapper for Ghostscript when converting from PostScript or PDF to an image format.
I think, this problem can only be solved to anybody's satisfaction once the efforts to add support for ICC profile handling and color management (currently underway) are completed for Ghostscript (design document as PDF). That point in time is close, however. If I understand recent commits to http://svn.ghostscript.com/trunk/ correctly, the next release (which will be dubbed 9.00 and out hopefully in August) will include support for color management via LittleCMS. Yay!
OSX 10.4 and up provide sips (scriptable image processing system) and it works well with PDF format. Perhaps it can be a temporary solution until Ghostscript supports color management.
Simple question - how is text-zooming implemented on an Android/iPhone device? Do they pre-compute frequently used bitmaps of a font and replace the text as the scale changes? Or do they extract the contours from the font files and render the text as vector graphics?
Text rendering is a fairly complex subject so any answer here will just be glossing over a lot of stuff. Typefaces are generally stored in vector format, and not bitmaps. The system lays out the text by computing the metrics of each letter and creates a vector shape that is rendered into a bitmap that is displayed on the screen. It's unlikely that the system will cache the individual letterforms as bitmaps because of the way antialiasing and subpixel rendering works. But at some point all vector graphics are converted into bitmaps because the typical computer display is made up of pixels.