Arvel  Miller

Arvel Miller

1624956517

Resize Image in Browser with High Quality and High Speed - Pica

pica - high quality image resize in browser

Resize images in browser without pixelation and reasonably fast. Autoselect the best of available technologies: webworkers, webassembly, createImageBitmap, pure JS.

demo

With pica you can:

  • Reduce upload size for large images, saving upload time.
  • Saves server resources on image processing.
  • Generate thumbnails in browser.

Note. If you need File/Blob resize (from form’s file input), consider use image-blob-reduce. It has additional machinery to process orientation, keep EXIF metadata and so on.

Migration from pica v6 to pica v7

Multiply unsharpAmount by 2, divide unsharpThreshold by 2, example:

  • pica@6: pica.resize(a, b, { unsharpAmount: 80, unsharpThreshold: 2 })
  • pica@7: pica.resize(a, b, { unsharpAmount: 160, unsharpThreshold: 1 })

Prior to use

Here is a short list of problems you can face:

  • Loading image:
    • Due to JS security restrictions, you can process images from the same domain or local files only. If you load images from remote domain use proper Access-Control-Allow-Origin header.
    • iOS has a memory limits for canvas elements, that may cause problems in some cases, more details.
    • If your source data is jpeg image, it can be rotated. Consider use image-blob-reduce.
  • Saving image:
    • Some ancient browsers do not support canvas.toBlob() method. Use pica.toBlob(), it includes required shim.
    • For jpeg source, it’s a good idea to keep exif data. Consider use image-blob-reduce.
  • Quality
    • JS canvas does not support access to info about gamma correction. Bitmaps have 8 bits per channel. That causes some quality loss, because with gamma correction precision could be 12 bits per channel.
    • Precision loss will not be noticeable for ordinary images like kittens, selfies and so on. But we don’t recommend this library for resizing professional quality images.

Install

npm install pica

Use

const pica = require('pica')();

// Resize from Canvas/Image to another Canvas
pica.resize(from, to, {
  unsharpAmount: 160,
  unsharpRadius: 0.6,
  unsharpThreshold: 1
})
.then(result => console.log('resize done!'));

// Resize & convert to blob
pica.resize(from, to)
  .then(result => pica.toBlob(result, 'image/jpeg', 0.90))
  .then(blob => console.log('resized to canvas & created blob!'));

API

new Pica(config)

Create resizer instance with given config (optional):

  • tile - tile width/height. Images are processed by regions, to restrict peak memory use. Default 1024.
  • features - list of features to use. Default is [ 'js', 'wasm', 'ww' ]. Can be [ 'js', 'wasm', 'cib', 'ww' ] or [ 'all' ].
  • idle - cache timeout, ms. Webworkers create is not fast. This option allow reuse webworkers effectively. Default 2000.
  • concurrency - max webworkers pool size. Default is autodetected CPU count, but not more than 4.
  • createCanvas - function which returns a new canvas, used internally by pica. Default returns a canvas element, but this function could return an OffscreenCanvas instead (to run pica in a Service Worker). Function signature: createCanvas(width: number, height: number): Canvas

Important! Latest browsers may support resize via createImageBitmap. This feature is supported (cib) but disabled by default and not recommended for use. So:

  • createImageBitmap() is used for non-blocking image decode (when available, without downscale).
  • It’s resize feature is blocked by default pica config. Enable it only on your own risk. Result with enabled cib will depend on your browser. Result without cib will be predictable and good.

resize(from, to, options) -> Promise

Resize image from one canvas (or image) to another. Sizes are taken from source and destination objects.

  • from - source, can be Canvas, Image or ImageBitmap.
  • to - destination canvas, its size is supposed to be non-zero.
  • options - quality (number) or object:
    • quality - 0…3. Default = 3 (lanczos, win=3).
    • alpha - use alpha channel. Default = false.
    • unsharpAmount - >=0, in percents. Default = 0 (off). Usually between 100 to 200 is good.
    • unsharpRadius - 0.5…2.0. By default it’s not set. Radius of Gaussian blur. If it is less than 0.5, Unsharp Mask is off. Big values are clamped to 2.0.
    • unsharpThreshold - 0…255. Default = 0. Threshold for applying unsharp mask.
    • cancelToken - Promise instance. If defined, current operation will be terminated on rejection.

Result is Promise, resolved with to on success.

(!) If you need to process multiple images, do it sequentially to optimize CPU & memory use. Pica already knows how to use multiple cores (if browser allows).

toBlob(canvas, mimeType [, quality]) -> Promise

Convenience method, similar to canvas.toBlob(), but with promise interface & polyfill for old browsers.

resizeBuffer(options) -> Promise

Supplementary method, not recommended for direct use. Resize Uint8Array with raw RGBA bitmap (don’t confuse with jpeg / png / … binaries). It does not use tiles & webworkers. Left for special cases when you really need to process raw binary data (for example, if you decode jpeg files “manually”).

  • options:
    • src - Uint8Array with source data.
    • width - src image width.
    • height - src image height.
    • toWidth - output width, >=0, in pixels.
    • toHeight - output height, >=0, in pixels.
    • quality - 0…3. Default = 3 (lanczos, win=3).
    • alpha - use alpha channel. Default = false.
    • unsharpAmount - >=0, in percents. Default = 0 (off). Usually between 50 to 100 is good.
    • unsharpRadius - 0.5…2.0. Radius of Gaussian blur. If it is less than 0.5, Unsharp Mask is off. Big values are clamped to 2.0.
    • unsharpThreshold - 0…255. Default = 0. Threshold for applying unsharp mask.
    • dest - Optional. Output buffer to write data, if you don’t wish pica to create new one.

Result is Promise, resolved with resized rgba buffer.

What is “quality”

Pica has presets to adjust speed/quality ratio. Simply use quality option param:

  • 0 - Box filter, window 0.5px
  • 1 - Hamming filter, window 1.0px
  • 2 - Lanczos filter, window 2.0px
  • 3 - Lanczos filter, window 3.0px

In real world you will never need to change default (max) quality. All this variations were implemented to better understand resize math :)

Unsharp mask

After scale down image can look a bit blured. It’s good idea to sharpen it a bit. Pica has built-in “unsharp mask” filter (off by default). Set unsharpAmount to positive number to activate the filter.

Filter’s parameters are similar to ones from Photoshop. We recommend to start with unsharpAmount = 160, unsharpRadius = 0.6 and unsharpThreshold = 1. There is a correspondence between UnsharpMask parameters in popular graphics software.

Browser support

We didn’t have time to test all possible combinations, but in general:

Note. Though you can run this package on node.js, browsers are the main target platform. On server side we recommend to use sharp.

References

You can find these links useful:

pica for enterprise

Available as part of the Tidelift Subscription.

The maintainers of pica and thousands of other packages are working with Tidelift to deliver commercial support and maintenance for the open source packages you use to build your applications. Save time, reduce risk, and improve code health, while paying the maintainers of the exact packages you use. Learn more.

Download Details:

Author: nodeca
The Demo/Documentation: View The Demo/Documentation
Download Link: Download The Source Code
Official Website: https://github.com/nodeca/pica
License: MIT

#image #pica #web-development #webdev

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Buddha Community

Resize Image in Browser with High Quality and High Speed - Pica
Arvel  Miller

Arvel Miller

1624956517

Resize Image in Browser with High Quality and High Speed - Pica

pica - high quality image resize in browser

Resize images in browser without pixelation and reasonably fast. Autoselect the best of available technologies: webworkers, webassembly, createImageBitmap, pure JS.

demo

With pica you can:

  • Reduce upload size for large images, saving upload time.
  • Saves server resources on image processing.
  • Generate thumbnails in browser.

Note. If you need File/Blob resize (from form’s file input), consider use image-blob-reduce. It has additional machinery to process orientation, keep EXIF metadata and so on.

Migration from pica v6 to pica v7

Multiply unsharpAmount by 2, divide unsharpThreshold by 2, example:

  • pica@6: pica.resize(a, b, { unsharpAmount: 80, unsharpThreshold: 2 })
  • pica@7: pica.resize(a, b, { unsharpAmount: 160, unsharpThreshold: 1 })

Prior to use

Here is a short list of problems you can face:

  • Loading image:
    • Due to JS security restrictions, you can process images from the same domain or local files only. If you load images from remote domain use proper Access-Control-Allow-Origin header.
    • iOS has a memory limits for canvas elements, that may cause problems in some cases, more details.
    • If your source data is jpeg image, it can be rotated. Consider use image-blob-reduce.
  • Saving image:
    • Some ancient browsers do not support canvas.toBlob() method. Use pica.toBlob(), it includes required shim.
    • For jpeg source, it’s a good idea to keep exif data. Consider use image-blob-reduce.
  • Quality
    • JS canvas does not support access to info about gamma correction. Bitmaps have 8 bits per channel. That causes some quality loss, because with gamma correction precision could be 12 bits per channel.
    • Precision loss will not be noticeable for ordinary images like kittens, selfies and so on. But we don’t recommend this library for resizing professional quality images.

Install

npm install pica

Use

const pica = require('pica')();

// Resize from Canvas/Image to another Canvas
pica.resize(from, to, {
  unsharpAmount: 160,
  unsharpRadius: 0.6,
  unsharpThreshold: 1
})
.then(result => console.log('resize done!'));

// Resize & convert to blob
pica.resize(from, to)
  .then(result => pica.toBlob(result, 'image/jpeg', 0.90))
  .then(blob => console.log('resized to canvas & created blob!'));

API

new Pica(config)

Create resizer instance with given config (optional):

  • tile - tile width/height. Images are processed by regions, to restrict peak memory use. Default 1024.
  • features - list of features to use. Default is [ 'js', 'wasm', 'ww' ]. Can be [ 'js', 'wasm', 'cib', 'ww' ] or [ 'all' ].
  • idle - cache timeout, ms. Webworkers create is not fast. This option allow reuse webworkers effectively. Default 2000.
  • concurrency - max webworkers pool size. Default is autodetected CPU count, but not more than 4.
  • createCanvas - function which returns a new canvas, used internally by pica. Default returns a canvas element, but this function could return an OffscreenCanvas instead (to run pica in a Service Worker). Function signature: createCanvas(width: number, height: number): Canvas

Important! Latest browsers may support resize via createImageBitmap. This feature is supported (cib) but disabled by default and not recommended for use. So:

  • createImageBitmap() is used for non-blocking image decode (when available, without downscale).
  • It’s resize feature is blocked by default pica config. Enable it only on your own risk. Result with enabled cib will depend on your browser. Result without cib will be predictable and good.

resize(from, to, options) -> Promise

Resize image from one canvas (or image) to another. Sizes are taken from source and destination objects.

  • from - source, can be Canvas, Image or ImageBitmap.
  • to - destination canvas, its size is supposed to be non-zero.
  • options - quality (number) or object:
    • quality - 0…3. Default = 3 (lanczos, win=3).
    • alpha - use alpha channel. Default = false.
    • unsharpAmount - >=0, in percents. Default = 0 (off). Usually between 100 to 200 is good.
    • unsharpRadius - 0.5…2.0. By default it’s not set. Radius of Gaussian blur. If it is less than 0.5, Unsharp Mask is off. Big values are clamped to 2.0.
    • unsharpThreshold - 0…255. Default = 0. Threshold for applying unsharp mask.
    • cancelToken - Promise instance. If defined, current operation will be terminated on rejection.

Result is Promise, resolved with to on success.

(!) If you need to process multiple images, do it sequentially to optimize CPU & memory use. Pica already knows how to use multiple cores (if browser allows).

toBlob(canvas, mimeType [, quality]) -> Promise

Convenience method, similar to canvas.toBlob(), but with promise interface & polyfill for old browsers.

resizeBuffer(options) -> Promise

Supplementary method, not recommended for direct use. Resize Uint8Array with raw RGBA bitmap (don’t confuse with jpeg / png / … binaries). It does not use tiles & webworkers. Left for special cases when you really need to process raw binary data (for example, if you decode jpeg files “manually”).

  • options:
    • src - Uint8Array with source data.
    • width - src image width.
    • height - src image height.
    • toWidth - output width, >=0, in pixels.
    • toHeight - output height, >=0, in pixels.
    • quality - 0…3. Default = 3 (lanczos, win=3).
    • alpha - use alpha channel. Default = false.
    • unsharpAmount - >=0, in percents. Default = 0 (off). Usually between 50 to 100 is good.
    • unsharpRadius - 0.5…2.0. Radius of Gaussian blur. If it is less than 0.5, Unsharp Mask is off. Big values are clamped to 2.0.
    • unsharpThreshold - 0…255. Default = 0. Threshold for applying unsharp mask.
    • dest - Optional. Output buffer to write data, if you don’t wish pica to create new one.

Result is Promise, resolved with resized rgba buffer.

What is “quality”

Pica has presets to adjust speed/quality ratio. Simply use quality option param:

  • 0 - Box filter, window 0.5px
  • 1 - Hamming filter, window 1.0px
  • 2 - Lanczos filter, window 2.0px
  • 3 - Lanczos filter, window 3.0px

In real world you will never need to change default (max) quality. All this variations were implemented to better understand resize math :)

Unsharp mask

After scale down image can look a bit blured. It’s good idea to sharpen it a bit. Pica has built-in “unsharp mask” filter (off by default). Set unsharpAmount to positive number to activate the filter.

Filter’s parameters are similar to ones from Photoshop. We recommend to start with unsharpAmount = 160, unsharpRadius = 0.6 and unsharpThreshold = 1. There is a correspondence between UnsharpMask parameters in popular graphics software.

Browser support

We didn’t have time to test all possible combinations, but in general:

Note. Though you can run this package on node.js, browsers are the main target platform. On server side we recommend to use sharp.

References

You can find these links useful:

pica for enterprise

Available as part of the Tidelift Subscription.

The maintainers of pica and thousands of other packages are working with Tidelift to deliver commercial support and maintenance for the open source packages you use to build your applications. Save time, reduce risk, and improve code health, while paying the maintainers of the exact packages you use. Learn more.

Download Details:

Author: nodeca
The Demo/Documentation: View The Demo/Documentation
Download Link: Download The Source Code
Official Website: https://github.com/nodeca/pica
License: MIT

#image #pica #web-development #webdev

I am Developer

1597469369

Crop and Resize Image Before Upload In Laravel Using with jQuery Copper JS

Crop and resize image size before upload in laravel using jquery copper js. In this post, i will show you how to crop and resize image size in laravel using jQuery copper js in laravel.

This laravel crop image before upload using cropper js looks like:

laravel crop image before upload

Laravel Crop Image Before Uploading using Cropper js Tutorial

Laravel crop image before upload tutorial, follow the following steps and learn how to use cropper js to crop image before uploading in laravel app:

  • Step 1: Install New Laravel App
  • Step 2: Add Database Details
  • Step 3: Create Migration & Model
  • Step 4: Add Route
  • Step 5: Create Controller By Artisan
  • Step 6: Create Blade View
  • Step 7: Make Upload Directory
  • Step 8: Start Development Server

Read More => https://www.tutsmake.com/laravel-crop-image-before-upload-using-jquery-copper-js/

Live Demo Laravel Crop image Before Upload.

#laravel crop image before upload, #laravel crop and resize image using cropper.js #ajax image upload and crop with jquery and laravel #crop and upload image ajax jquery laravel #crop image while uploading with jquery laravel #image crop and upload using jquery with laravel ajax

I am Developer

1616903936

Node JS Resize Image Before Upload Example

Resize image before upload using multer, sharp with node js and express js. In this node js tutorial, you will learn how to resize image before upload using multer, sharp with node js and express js.

Image upload is the basic requirement of any application. So this example will guide you step by step on how to resize image before upload using multer in node js. And you can understand a concept of node js compress image before upload.

Node Express Resize Image Before Upload Tutorial Example

Step 1 - Create Node JS App

Step 2 - Install Express and Multer Dependencies

Step 3 - Import Dependencies in Server.js File

Step 4 - Create Server.js File

Step 5 - Create Form

Step 6 - Run Development Server

https://www.tutsmake.com/node-js-resize-image-before-upload-using-multer-sharp-example/

#how to upload multiple image in node js #resize image in nodejs #image processing in node js #node js image upload resize

I am Developer

1597564621

Laravel 7/6 Intervention Image Resize

laravel intervention image upload and resize tutorial. Here, i will show you how to resize image before upload using intervention image package in laravel.

Laravel Intervention Resize Image Upload and Save to Storage

Use the following steps and image upload in laravel using intervention package with save to storage:

  1. Install Laravel App
  2. Setup Database
  3. Install Image Intervention Package
  4. Generate Image migration file and model
  5. Make Upload And Resize Image Route
  6. Create Upload And Resize Image Controller & Methods
  7. Create Blade View
  8. Make Folder
  9. Start Development Server

https://www.tutsmake.com/laravel-intervention-image-upload-using-ajax/

#laravel intervention image resize #laravel intervention image upload #laravel intervention image save to storage #laravel intervention image thumbnail #laravel intervention image compression

John Smith

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PHP Crop Image While Uploading with Cropper JS

Are you looking for tutorial on How to Crop image before uploading of image when user has click on Upload button. How to get the Cropped image in PHP and upload to server. If yes, the you have find the right web page, this is because in this tutorial we have step by step descript how to implement Cropper.js jQuery plugin for crop image and then after upload on to server using PHP script with Ajax. In this tutorial we have use Cropper.js javascript library for crop image and for upload image we have use Ajax which will send cropped image data to php script for upload on to server. In this post you can find complete source code with video tutorial also.

For more information - https://www.webslesson.info/2020/08/php-crop-image-while-uploading-with-cropper-js.html

#cropper js example #image crop #image cropper #image cropper js #image crop and resize #image crop before upload