Hybrid image aliasing #44803
Closed
Hybrid image aliasing #44803
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
facebook-github-bot
added
the
CLA Signed
|
This pull request was exported from Phabricator. Differential Revision: D58120352 |
Summary: This change introduces a new prop to the Android `Image` component: `resizeMultiplier`. This prop can be used when the `resizeMethod` is set to `resize`, and it directly modifies the resultant bitmap generated in memory from Fresco to be larger (or smaller) depending on the multiplier. A default of 1.0 means the bitmap size is designed to fit the destination dimensions. A multiplier greater than 1.0 will set the `ResizeOptions` provided to Fresco to be larger that the destination dimensions, and the resulting bitmap will be scaled from the hardware size. This new prop is most useful in cases where the destination dimensions are quite small and the source image is significantly larger. The `resize` resize method performs downsampling and significant image quality is lost between the source and destination image sizes, often resulting in a blurry image. By using a multiplier, the decoded image is slightly larger than the target size but smaller than the source image (if the source image is large enough). It's important to note that Fresco still chooses the closest power of 2 and will not scale the image larger than its source dimensions. If the multiplier yields `ResizeOptions` greater than the source dimensions, no downsampling occurs. Here's an example: If you have a source image with dimensions 200x200 and destination dimensions of 24x24, a `resizeMultiplier` of `2.0` will tell Fresco to downsample the image to 48x48. Fresco picks the closest power of 2 (so, 50x50) and decodes the image into a bitmap of that size. Without the multiplier, the closest power of 2 would be 25x25, which is half the quality. ## Changelog [Android][Added] - Adds a new `Image` prop `resizeMultiplier` to help increase quality of small images on low DPI devices Differential Revision: D58120352
Abbondanzo
force-pushed
the
export-D58120352
branch
from
bf47bcc
to
01cb923
Compare
|
This pull request was exported from Phabricator. Differential Revision: D58120352 |
Base commit: a569c82 |
|
This pull request has been merged in b6c3433. |
|
This pull request was successfully merged by Peter Abbondanzo in b6c3433. When will my fix make it into a release? | How to file a pick request? |
This was referenced Jun 20, 2024
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Summary:
This change introduces a new prop to the Android
Imagecomponent:resizeMultiplier. This prop can be used when theresizeMethodis set toresize, and it directly modifies the resultant bitmap generated in memory from Fresco to be larger (or smaller) depending on the multiplier. A default of 1.0 means the bitmap size is designed to fit the destination dimensions. A multiplier greater than 1.0 will set theResizeOptionsprovided to Fresco to be larger that the destination dimensions, and the resulting bitmap will be scaled from the hardware size.This new prop is most useful in cases where the destination dimensions are quite small and the source image is significantly larger. The
resizeresize method performs downsampling and significant image quality is lost between the source and destination image sizes, often resulting in a blurry image. By using a multiplier, the decoded image is slightly larger than the target size but smaller than the source image (if the source image is large enough).It's important to note that Fresco still chooses the closest power of 2 and will not scale the image larger than its source dimensions. If the multiplier yields
ResizeOptionsgreater than the source dimensions, no downsampling occurs.Here's an example:
If you have a source image with dimensions 200x200 and destination dimensions of 24x24, a
resizeMultiplierof2.0will tell Fresco to downsample the image to 48x48. Fresco picks the closest power of 2 (so, 50x50) and decodes the image into a bitmap of that size. Without the multiplier, the closest power of 2 would be 25x25, which is half the quality.Changelog
[Android][Added] - Adds a new
ImagepropresizeMultiplierto help increase quality of small images on low DPI devicesDifferential Revision: D58120352