Declaration

function IEEstimateImageQuality(const FileName: WideString): Integer; overload;
function IEEstimateImageQuality(Stream: TStream; ImageType: TIOFileType): Integer; overload;

Description

Estimates the quality that was used for saving a JPEG HEIF/HEIC, AVIF or WebP file.
The returned value can then be used for the ImageQuality property (to maintain a similar quality level).
Result will be -1 if an error is encountered, e.g. for an image that is not available or not a supported format.

Note:
◼For JPEG, it uses the (highly accurate) IECalcJpegFileQuality
◼For other formats it performs a calcutation based on the bits per pixel. Results will not be particularly accurate, and one of: 30, 50, 65, 75, 85, 90, 95, 100

Example

ImageEnView1.LoadFromFile( 'C:\input.heic' );
// do image processing here...
ImageEnView1.IO.Params.ImageQuality := IEEstimateImageQuality('C:\input.heic');
ImageEnView1.IO.SaveToFile('D:\output.heic');

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