Saving Pure Filtered Image

[okaforcj]

Hello, I am making an app to apply filters to an image. I am able to apply a color matrix on the loaded image on the front end and show visually. I was wondering if the canvas had a way of extracting the full and only the image data and making a snapshot of just the filtered full image that because I want to send it to the backend/ save it to cloud storage/save it to users phone. I am just trying to ensure that there is no information lost in the original image, the filters are applied correctly and i could extract the full byte information without any noise from the rest of the canvas. I've see the makeImageSnapshot, but I'm not sure it does what I'm looking for exactly, can I get any advice on this please

[wcandillon]

You can use the picture PictureRecorder to get a binary representation of the image + the skia operations applied to it.
You can convert these pictures into png encoded image on your backend (if you have Skia available).
Currently makeImageSnapshot is actually using the picture recorder to get the png of the canvas.
We may offer a way to go from Picture to an Image directly. Right now makeImageSnapshot is your best bet. Let us know if you have specific requirements such as scaling the picture before converting it into an image.

[okaforcj]

yes please could you please advise how to scale the image to the original size and also do you have advice on the quality of the image recorded by the PictureRecorder

[wcandillon]

if you want the size of the image as it was on the device, I recommend using makeImageSnapshot.
In Skia, the word "Picture" (and Picture recording) refers to a binary format where you can store drawing operations for debugging for instance (https://skia.org/docs/dev/tools/debugger/). These "pictures" can be encoded into images.

[okaforcj]

Spot on thanks, ill use the makeImageSnapshot. Thanks for the advice, I'm just gonna use .