Image.equals() throws java.lang.UnsupportedOperationException about scrimage HOT 11 CLOSED

I corrected the bug.

But I should warn you that most of the time image won't be equal to image removeTransparency(white).
Indeed remove transparency convert the type of the Image to something where you can't write 'alpha' channel anymore, so the equality breaks.
If you are interested only in the value of the pixels you should compare _.pixels.toList.

It will likely be pushed soon in the maven repo, in the meanwhile you can use the stable branch of the repository.

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Thank you. I am trying to find ways to detect if the alpha channel is in use, and my first naive idea was to removeTransparency and check for equality. If you can recommend a way of checking for use of alpha channel, please let me know.

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Currently there is no constant time method to do that, because all images automatically receive an alpha channel when loaded. The alpha channel can be removed trough removeTransparency.

So in the current version I think the more efficient is:

image.pixels map( _ >> 24) forall( _ == 0xff )

It will return true when the alpha channel of the image is not used.

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Thanks for deploying to maven repo. On a sidenote, can you depend on a git-subfolder in SBT? I added dependency (see below), but the scrimage classes was not available. In the output I saw SBT downloaded 1.4.2, which I then switched to eventually.

lazy val scrimage = RootProject(uri("git://github.com/sksamuel/scrimage.git/core#stable"))

val main = play.Project(appName, appVersion, libraryDependencies).dependsOn(scrimage).settings(

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Sometimes it takes a while to appear on maven

On 27 August 2014 12:09, René Grüner Vangsgaard [email protected]
wrote:

Thanks for deploying to maven repo. On a sidenote, can you depend on a
git-subfolder in SBT? I added dependency (see below), but the scrimage
classes was not available. In the output I saw SBT downloaded 1.4.2, which
I then switched to eventually.

lazy val scrimage = RootProject(uri("git://github.com/sksamuel/scrimage.git/core#stable"))

val main = play.Project(appName, appVersion, libraryDependencies).dependsOn(scrimage).settings(

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#55 (comment).

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You may have misunderstood me - I am using the newest version with the fix (1.4.2) from maven, hence my thanks for deploying to maven repo :)

I did have troubles when I tried using the stable version from github, as the core is a subfolder/subproject of the root.

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ah ok

On 27 August 2014 12:32, René Grüner Vangsgaard [email protected]
wrote:

You may have misunderstood me - I am using the newest version with the fix
(1.4.2) from maven, hence my thanks for deploying to maven repo :)

I did have troubles when I tried using the stable version from github, as
the core is a subfolder/subproject of the root.

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#55 (comment).

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@gwenzek your alorithm returns false on a JPG image (notice, it is a jpeg even though it status png).

    def getImageContents(url: String): Array[Byte] = {
        import scala.language.postfixOps
        import scala.io._
        import scala.sys.process._
        import java.io.{ByteArrayOutputStream, File, InputStream}
        import java.net.URL

        val image = new ByteArrayOutputStream()
    new URL(url) #> image ! ;
    image.toByteArray
    }

scala> com.sksamuel.scrimage.Image(util.ResizeImages.getImageContents("http://i.imgur.com/7ce5j26s.png")).pixels map(_ >> 24) forall(_ == 0xff)
res8: Boolean = false

Additionally it seems like the BufferedImage.getcolorModel.isAlpha is wrong as well:

com.sksamuel.scrimage.Image(util.ResizeImages.getImageContents("http://i.imgur.com/7ce5j26s.png")).toBufferedImage.getColorModel.hasAlpha

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I forgot a part:

def useAlpha(img: Image): Boolean = !(img.pixels map( _ >> 24 & 0xff) forall( _ == 0xff ))

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9b4de9e adds a usesAlpha method to Image.

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Thanks - helps a pixel-ignorant like me a lot.

I am still baffled by the behaviour or the JDK method BufferedImage.getColorModel.hasAlpha on JPG a image.

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