I would like to know how to obtain image size using Corona without loading them and call obj.width.
Is there a way?
if your image is PNG, Yeah!
http://developer.coronalabs.com/forum/2012/05/16/pnglib-extract-data-png-files-width-height-color-depth-etc
Even for jpeg images, I think someone suggested a way.
Related
I googled and even asked chatGPT but I'm unable to find a solution and hope to get some guidance here.
First I've to mention that I'm not a programmer but rather a beginner.
Following a short description of what I'm trying to achive and what I've done so far.
I gather data and create a circular visualization using Circos which produces SVG
and PNG images.
(unfortunately the PNG doesn't give me the option of searching for
text an make replaecments), nevertheless I can use them to sucessfuly produce a
MPEG movie using FFmpeg. Therefore I need to use the SVG output to apply the
desired changes.
So I tried to use CairoSVG to render the SVG file to a PNG image but it does not
render emojis by default because the are not part of the SVG specification and
CairoSVG only supports features defined in the SVG specification. The Emojis are
stored as Unicode characters and are not natively supported in SVG
Next I tried to use PIL (Python Imaging Library) as it provides support for Unicode
characters, including emojis, when converting images to and from various formats.
Unfortunately PIL does not have native support for converting SVG files to PNG and
it seems that PIL is primarily designed for creating and manipulating images in a
variety of formats, but does not have built-in support for reading or converting
SVG files.
So now my questions are:
Would FFmpeg give me the desired results, if I compile it using the --enable-
librsvg option so it can convert a sequence of SVG images to a video but i'm not
sure if it supports emojis rendered correctly and want to spare me the hassle as
I'm pretty sure to struggle compiling it on my Mac running Ventura?
Are the maybe other ways or posibilities to solve that problem?
Many thanks in advance for your help or any hint :-)
Have all a nice weekend and take care
Regards,
Deekee
NB: an example of the circular visualization can be found here animated graph and the static version annotated graph
Problem solved, I used the html2image Python module which converts the SVG (including embedded Emoji's) nicely to a PNG image an then use those images to create a MPG4 video using FFmpeg.
I'm looking for an all-in-one solution for processing web images
Resizing
Cropping
Save as WEBP / JPEG / PNG
Drawing simple rectangles
Adding text
Reducing colors (quantization) for PNG
The only thing I'm not clear about is PNG quantization. Currently I'm using pngquant which works great, but I'd prefer to do everything in one place.
I see the SkiaSharp has SKImage.Encode() which takes a quality parameter. However there's no explanation as to what it actually is. Will this give me color quantization for PNG files? If not, is there something else in the library to do this?
I am building a small app with nodejs/expressjs. I made an upload wizard for GIF and JPG images... Depend on images' extension I will classify them into Animated Images or Normal Images...
GIF --> Animated Images
JPG --> Normal Images
But I got a problem, images in JPG can be animated. So how can I detect animated JPG images?
Demo animated JPG: http://picforest.net/pic/0237bbca82954e74902a4afba66df221
I think you can find out that information using EXIF information.
For instance, here's the EXIF info of the image that you have provided:
http://regex.info/exif.cgi?imgurl=http%3A%2F%2Fcdn.picforest.net%2Fupload%2F2015%2F17%2F0237bbca82954e74902a4afba66df221.jpg
It says that it's a GIF image.
There's a node module for exif called https://github.com/gomfunkel/node-exif. Perhaps that may help you out
As it was pointed in comments, there is no such thing as animated JPEGs (except this obscure proposal). Unfortunately this not mean that you can rely on image extension. Extension is just part of file name, it suggest file type, but not determines it. For example image you shared has .jpg extension, but in reality it's GIF and every major browser will treat it as one. In order to detect animated image you must inspect it's content. For example in case of GIF images you could check if first 6 bytes of file is GIF89a or GIF87a, but doing so you will know only that image is a GIF, not that image is an animated GIF. If you want to detect only animated GIFs you must check if they have multiple Image Descriptor Blocks, and it's a little bit more complicated.
It's also worth to mention that currently there are 3 supported by browsers image formats which could contain animation:
GIF - it's rather obvious;
APNG - it's supported by Firefox and Safari, other browsers displays these images as ordinary PNGs;
SVG - SMIL animations are supported by all major browsers except IE and Edge, and there are also CSS and ECMAScript animations.
If you want to detect first two types of animation you can use my node.js library - is-animated, it's rather simple to use:
const isAnimated = require('is-animated');
isAnimated(someBuffer); // -> true/false
Unfortunately currently it doesn't support detecting animated SVGs.
I've been playing with jssor sliders, specifically with different-size-photo-slider. It works when I run the demo version, but when I add my own jpegs, generated by Aperture on OS X from RAW format, those images never finish loading. The loading animated icon just stays forever. The files and pixel sizes are not different from the jssor images. It looks like my jpegs fail to be resized. I tried both Safari and Firefox. Any ideas?
Thanks.
It looks like when I export from Aperture with the default colormap, which is sRGB IEC611966-2.1, javascript has problems resizing the picture. Using, or maybe just changing to, Adobe 1998 or Generic RGB makes things work fine. BTW. the source is Nikon raw file with sRGB color map.
While I have read in the Microsoft guidelines that we should prefer SVG images over raster images I cannot seem to find anywhere how to use them for the logos in the manifest. Does anyone know if this possible?
As Hans already mentioned only PNG and JPEG images are supported. Here's official documentation on the matter containing complete info on image sizes as well.