I need resize/corp image to 96x96 and the file size under 5k. How to set ImageResizer to achieve these goal?
With ImageResizer.Net you can specify with (?w=96) and height=(&h=96) for the width and decide on the scaling model e.g. (&mode=max)
However you cannot specify max size, you can experiment with both the file format (format=gif|png|jpg) or/and quality (q=50 (0..100)) to find the best setting for a range of images
More info available at http://imageresizing.net/docs/basics
Thanks
Shane
Related
I have a tflite model trained on BGR data. How can I make it work properly with RGB images?
UPDATE
I want to use it with the material-showcase app: https://github.com/googlesamples/mlkit/tree/master/android/material-showcase
#Farmaker #JaredJunyoungLim . Thank you very much for your answers. I've updated the question. At first I was thinking about converting the model itself, so it wouldn't require any changes in the code. For example, the converter to the OpenVINO format has an option to reverse input channels. I have also tried to set the BGR ColorSpace in the metadata, but have found out that it's most probably not possible.
I guess I'll go with your suggestion then. In the linked code, there is indeed the ByteBuffer (FrameProcessorBase.kt). I guess this is the place to change the order of the channels (after the line 70):
val frame = processingFrame ?: return
However, how can I change the order of channels, if this is just a ByteBuffer? Do I need to figure out the way data is stored in it? For example there is R,G,B,R,G,B,R,G,B,... etc. for every pixel? Or maybe there is some more elegant way to that?
I can see that the format is set to IMAGE_FORMAT_NV21, which is YCrCb
UPDATE 2
For what I've tested (
Log.d("ByteBuffer", frame.toString())
), it seems that the ByteBuffer takes 1.5 bytes per pixel:
java.nio.HeapByteBuffer[pos=0 lim=3110401 cap=3110401]
(Resolution: 1920x1080; 3110400/1920/1080=1.5)
So it uses 12 bits per pixel, which means 4 bits per channel per pixel. That's a bit strange, because I would suspect at least 8 bits per channel per pixel (0-255).
So I guess that maybe it's compressed.
What i say in the title is what i'm doing manually right now for 30 levels!
I'm building different color tshirt previews, every level represents a color and there's a level on top with the draw to be printed.
If I can do it automatically I'll have lot of time saved!
Anybody can help?
Use convert from the ImageMagick tools:
convert multilayer.xcf output.png
The result will be a separate PNG for each layer:
output-0.png
output-1.png
output-2.png
[…]
And: don't use JPG if you continue to print it on T-Shirts… JPG is lossy and doesn't support alpha-channels, which is important for most T-Shirt prints.
i want to shrink png or jpg on OSX. i only want to shrinkg without affecting the image quality.
like tinypng.org
is there any recommended library? i just know imagemagick. is there a way to do that natively? or another library to shrink/compress images without affecting the image quality?
my aim is to shrink the file size, for example:
logo.png >> 476 k before shrink
logo.png >> 50k after shrink
Edit: to be clear, i want to compress the size of the file, not the image resolution.
TinyPNG.org works by using image quantisation - the similar colours in the image are converted into a HSV or RGB model and then merged depending on the distance.
How does it work?
...
When you upload a PNG (Portable Network Graphics) file, similar colours in your image are combined. This technique is called “quantisation”
...
src: http://tinypng.org
An answer here outlines a method of doing so: https://stackoverflow.com/a/492230/556479.
There are also some answers on this question with refer to how you can do so on Mac OS using objective-c: How do I reduce a bitmap to a known set of RGB colours
See Wikipedia for a more in depth guide: http://en.wikipedia.org/wiki/Color_quantization
Did you have a problem using ImageMagick? It has a rich set of quantize functions such as
bool MagickQuantizeImage( MagickWand mgck_wnd,
float number_colors,
int colorspace_type,
float treedepth,
bool dither,
bool measure_error )
Here is a very thorough guide to quantization using imageMagick
My suggestion is to use http://pngnq.sourceforge.net, it will give better results than ImageMagick and for the single example given in http://tinypng.org, it also produces a very similar output. It is a tiny C implementation of the method present in the paper "Kohonen Neural Networks for Optimal Colour Quantization". That alone is much better since you are no longer relying on closed unknown implementations.
Original (57 KB), tinypng.org (16 KB), pngnq (17 KB):
Using ImageMagick, the best quantization to 256 colors I can get uses the LAB colorspace and dithering by Floyd-Steinberg:
convert input.png -quantize LAB -dither FloydSteinberg -colors 256 output.png
This produces a 16 KB png, but it contains much more visual artifacts:
I have a camera which produces photographs of 3008x2000 pixels. I use Image Magick to scale and resize the photos to be put up on my website. The size of the images I am using on the website is 602x400. I use this command to reduce the size:
convert DSC_0124.JPG -scale 20% -size 24% img1.jpg
This produces an image which is 602x400 pixels in size. But the file size will be always above 250KB. More images on a single html page means the page will be heavier and loading time will be longer. Are there any features in image magic that will help me to keep the file size as small as possible, possibly, below 100KB. But the image size should be the same, that is, 602x400px. I have achieved similar optimisation with SEAMonster tool for MS Windows. As it doean't have a commandline alternative, it wouldn't be of much help when there are hundreds of images to be converted.
Use command as Delan proposed with additional "-strip" flag to remove EXIF data, this have reduced the size of some of my images drastically. Here is a bash script for unix platforms, but you can use the second part only for individual images.
for X in *.jpg; do convert "$X" -resize 602x400 -strip -quality 86 "$X"; done
This will convert all images in the directory.
Use -quality to set the compression level:
convert DSC_0124.JPG -scale 20% -size 24% -quality [0..100] img1.jpg
You can define the maximum size of the output image at 100KB like this:
convert DSC_0124.JPG -resize 602x400! -strip -define jpeg:extent=100KB img1.jpg
If you are running your website on PHP, you might want to consider the SLIR image resizing script, it does a great job resizing to various constraints (see below) and caches the results.
Parameters:
w Maximum width
h Maximum height
c Crop ratio
q Quality
b Background fill color
p Progressive
http://shiftingpixel.com/2008/03/03/smart-image-resizer/
http://code.google.com/p/smart-lencioni-image-resizer/
When I try to run a bunch of PNG-8 images with alpha transparency through Imagemagick, it converts them to PNG-32, increasing the file size a lot.
Is it possible to force Imagemagick to keep my image type as 8-bit PNG?
You can do it like this:
convert test.png PNG8:test2.png
I've had varying luck with IM and PNG8, but this is the correct way to do it.
I seem to get the best result using the following
convert src.png -colors 256 PNG8:dest.png